JP5802549B2 - Power supply device and power supply system using the same - Google Patents

Description

  The present invention relates to a switching power supply device capable of parallel or series operation and a power supply system using the same.

  A switching power supply apparatus including a DC-DC converter generally includes a power conversion circuit that converts an input voltage into a predetermined output voltage by turning on and off the main switching element, and a control that defines the on time and off time of the main switching element. A control circuit that generates a signal and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal.

  When building a power supply system that operates multiple switching power supplies in parallel and supplies power to a common load, the output current of each switching power supply is automatically balanced so that the load is not concentrated on a specific switching power supply. A switching power supply device having a function to be selected is selected. There are various methods for balance control of the output current, but in the case of a switching power supply with a high power of several hundred watts or more, the control circuits of each switching power supply communicate with each other, and the difference between the output currents becomes small. As described above, a method of individually adjusting the on time and the off time of each main switching element is often used.

  Conventionally, as disclosed in, for example, Patent Document 1, since the control circuits of a plurality of switching power supply devices communicate with each other, the current balance terminals are connected by a current balance line, and one end of the load is connected. There is a parallel operation power supply system in which negative output terminals are connected by a negative output line. The control circuit of each switching power supply device converts its output current into analog voltage information, and exchanges the analog voltage information through the current balance line and the negative output line so that the output currents are equal to each other. ON / OFF control. Furthermore, the reference voltage terminals of each switching power supply device are connected by a reference voltage balance line, and a reference voltage (analog voltage information) of a specific switching power supply device is sent to another switching power supply device through the reference voltage balance line and the negative output line. In addition, a configuration that facilitates balance control of output current by sharing a reference voltage is also disclosed.

  In this parallel operation power supply system, if a plurality of switching power supply devices having the same specification are prepared and wired, the output current balance control is automatically performed, and the number of parallel power supplies can be increased or decreased freely.

  In addition, as disclosed in Patent Document 2, there is a multi-parallel power supply device in which a plurality of switching power supply devices (power supply blocks) operated in parallel and a dedicated host control circuit are combined. In this multi-parallel power supply unit, analog control is performed through a local feedback path provided for each switching power supply unit in a relatively high frequency band in output voltage control, and a relatively low frequency band is common to each power supply block that passes through a host control circuit. Digital control through the global feedback path. Further, the balance control of the output current performs a complex control by the current feedback path provided for each switching power supply device and the global feedback path, and balances the average output current.

  This multi-parallel power supply unit connects digital switching (output voltage control) with high noise resistance and composite control (balance control of output current) through a global feedback path that connects multiple switching power supply units, resulting in long wiring. Thus, analog control (output voltage control) excellent in high-speed response is performed through a local feedback path that can be wired short for each switching power supply device. Also disclosed is a multi-parallel power supply device configured by combining a host control circuit in a master power supply and a plurality of slave power supplies.

  As disclosed in Patent Document 3, there is a power supply system in which a plurality of switching power supply devices (POL regulators) and a dedicated system controller are combined. In the switching power supply used in this power supply system, a control circuit or the like is configured by a digital processor such as a microcontroller or a DSP, and a communication system based on I2C (Inter Integrated Circuit) is used to communicate with an external system controller. Two-way communication with. Although not described in the specification of Patent Document 3, etc., when performing parallel operation of a plurality of switching power supply devices, the system controller centrally manages the output voltage and output current of each switching power supply device, and each switching power supply device It is considered that the output current can be balanced by sending a control correction command to the control circuit.

JP 2007-143292 A JP 2010-142077 A US7,000,125 gazette

  In the case of the switching power supply device and the parallel operation power supply system disclosed in Patent Document 1, since the balance control of the output current of the switching power supply device is performed by analog control, the configuration of the circuit for balance control becomes complicated and the number of parts increases. In addition, it is inevitable that the wiring of the current balance line, the reference voltage balance line, and the negative output line will be long to some extent, but since the exchange of information between each switching power supply device is performed using an analog voltage signal, Prone to malfunction due to noise and other effects. In addition, it is possible to insulate and transmit each signal, but in consideration of transmitting an analog signal with high accuracy, isolation is not easy.

  In the case of the multi-parallel power supply device of Patent Document 2, a dedicated host control circuit must be prepared in addition to a plurality of switching power supply devices, and the entire device tends to be large. Even if the host control circuit is built in the switching power supply device that becomes the master power supply, two types of switching power supply devices, the master power supply and the slave power supply, must be prepared. Increase.

  In the case of the power supply system of Patent Document 3, a communication system based on the I2C method is employed, so that there are at least two communication signal lines (synchronous clock signal lines and data) for connecting the switching power supply devices. Signal line). Furthermore, in order to avoid mutual interference due to capacitive coupling between the signal lines, the signal lines must be routed along the ground line. Therefore, particularly when a power supply system is constructed using a large number of switching power supply devices, there is a problem that wiring of communication signal lines becomes very complicated. Since the I2C system performs one-to-many bidirectional communication, it must have address information of the switching power supply in addition to data information. Normally, address information and data information are transmitted in separate and independent frames, and there is no error detection such as parity in the frame. For example, if a bit error occurs in address information due to the influence of external noise, etc. Data information is likely to be transmitted to a different switching power supply device and communication reliability is very low. Furthermore, since the I2C module is a communication module having a higher function than the UART module, it is mounted only on a relatively expensive digital processor.

  The present invention has been made in view of the above-described background art, and is a switching power supply device that can communicate with a small number of wires using a general-purpose UART module and can easily perform balance control during parallel and series operation. The purpose is to provide a power supply system.

The power conversion circuit according to claim 1 converts an input voltage supplied to an input terminal into a DC voltage by a switching operation of a main switching element, and supplies an output voltage and an output current to a load connected to the output terminal. A control circuit that generates a control signal that defines an on time and an off time of the main switching element, and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal. Switching power supply,
An output voltage detection circuit for detecting the output voltage or a voltage corresponding thereto and outputting an output voltage signal; and an output current detection circuit for detecting the output current or a current corresponding thereto and outputting an output current signal;
The control circuit includes a receiving unit having an RX terminal which is a high impedance input, and a communication UART composed of a transmitting unit having a TX terminal which is an output capable of changing to a low level, a high level or a high impedance. A voltage setting for determining a target value of the output voltage, the module, the output voltage signal, the output current signal, a mode setting signal for designating either the master mode or the slave mode, and a signal capable of external input A control unit that receives a signal and controls communication by the UART module and generates the control signal;
The UART module can perform external communication through an INF line that connects the RX terminal and the TX terminal to each other and a GND line that is a ground potential of the UART module.
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. A switching power supply that maintains the transmitter of the UART module at high impedance and generates the control signal so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the receiver. is there.

According to a second aspect of the present invention, there is provided a power conversion circuit for converting an input voltage supplied to an input terminal into a DC voltage by a switching operation of a main switching element and supplying an output voltage and an output current to a load connected to the output terminal. A control circuit that generates a control signal that defines an on time and an off time of the main switching element, and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal. Switching power supply,
An output voltage detection circuit for detecting the output voltage or a voltage corresponding thereto and outputting an output voltage signal; and an output current detection circuit for detecting the output current or a current corresponding thereto and outputting an output current signal;
The control circuit includes a receiving unit having an RX terminal which is a high impedance input, and a communication UART composed of a transmitting unit having a TX terminal which is an output capable of changing to a low level, a high level or a high impedance. A voltage setting for determining a target value of the output voltage, the module, the output voltage signal, the output current signal, a mode setting signal for designating either the master mode or the slave mode, and a signal capable of external input A control unit that receives a signal, controls communication by the UART module and generates the control signal, and a first photocoupler whose input and output are insulated by a first light emitting diode on the input side and a first phototransistor on the output side And a second photodiode whose input and output are insulated by a second light emitting diode on the input side and a second phototransistor on the output side. Coupler and is provided,
One end of the first phototransistor is connected to the RX terminal, one end of the second light emitting diode is connected to the TX terminal, and the other end of the first phototransistor and the other end of the second light emitting diode are connected to the UART. Connected to the module ground potential,
The UART module has an INF line connecting one end of the first light emitting diode and one end of the second phototransistor, and connects the other end of the first light emitting diode and the other end of the second phototransistor. External communication is possible through the GND line
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. A switching power supply that maintains the transmitter of the UART module at high impedance and generates the control signal so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the receiver. is there.

According to a third aspect of the present invention, there is provided a power conversion circuit for converting an input voltage supplied to an input terminal into a DC voltage by a switching operation of a main switching element and supplying an output voltage and an output current to a load connected to the output terminal. A control circuit that generates a control signal that defines an on time and an off time of the main switching element, and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal. Switching power supply,
An output voltage detection circuit that detects the output voltage or a voltage corresponding to the output voltage and outputs an output voltage signal, and a temperature detection circuit that detects the temperature of a specific component and outputs a temperature signal are provided,
The control circuit includes a receiving unit having an RX terminal that is a high impedance input and a transmitting unit having a TX terminal that is an output that can be changed to a low level, a high level, or a high impedance. UART module, the output voltage signal, the temperature signal, a mode setting signal for designating either the master mode or the slave mode, and a signal that can be externally input, and a voltage setting that determines the target value of the output voltage A control unit that receives a signal and controls communication by the UART module and generates the control signal;
The UART module can perform external communication through an INF line that connects the RX terminal and the TX terminal to each other and a GND line that is a ground potential of the UART module.
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. A switching power supply that maintains the transmitter of the UART module at high impedance and generates the control signal so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the receiver. is there.

According to a fourth aspect of the present invention, there is provided a power conversion circuit for converting an input voltage supplied to an input terminal into a DC voltage by a switching operation of a main switching element and supplying an output voltage and an output current to a load connected to the output terminal. A control circuit that generates a control signal that defines an on time and an off time of the main switching element, and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal. Switching power supply,
An output voltage detection circuit that detects the output voltage or a voltage corresponding to the output voltage and outputs an output voltage signal, and a temperature detection circuit that detects the temperature of a specific component and outputs a temperature signal are provided,
The control circuit includes a receiving unit having an RX terminal that is a high impedance input and a transmitting unit having a TX terminal that is an output that can be changed to a low level, a high level, or a high impedance. UART module, the output voltage signal, the temperature signal, a mode setting signal for designating either the master mode or the slave mode, and a signal that can be externally input, and a voltage setting that determines the target value of the output voltage A control unit that receives a signal, controls communication by the UART module and generates the control signal, and a first photocoupler whose input and output are insulated by a first light emitting diode on the input side and a first phototransistor on the output side And a second photocathode whose input and output are insulated by a second light emitting diode on the input side and a second phototransistor on the output side. La and is provided,
The one end of the first phototransistor is connected to the RX terminal, the one end of the second light emitting diode is connected to the TX terminal and the other end the UART of the other end and the second light emitting diode of the first phototransistor Connected to the module ground potential,
The UART module, the first light emitting diode end and said second phototransistor one end and an INF line connected to each other, and connecting the other ends of said second phototransistor of the first light emitting diode with each other External communication is possible through the GND line
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. A switching power supply that maintains the transmitter of the UART module at high impedance and generates the control signal so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the receiver. is there.

  According to a fifth aspect of the invention, in addition to the configuration of the first aspect, a temperature detection circuit that detects a temperature of a specific component and outputs a temperature signal is provided, and the control circuit further includes the output voltage signal, The switching power supply apparatus is provided with a control unit that receives an output current signal, the temperature signal, the mode setting signal, and the voltage setting signal, and controls communication by the UART module and generates the control signal.

According to a sixth aspect of the present invention, there is provided a power conversion circuit for converting an input voltage supplied to an input terminal into a DC voltage by a switching operation of a main switching element and supplying an output voltage and an output current to a load connected to the output terminal. A control circuit that generates a control signal that defines an on time and an off time of the main switching element, and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal. Switching power supply,
An output voltage detection circuit that detects the output voltage or a voltage corresponding thereto and outputs an output voltage signal, an output current detection circuit that detects the output current or a current corresponding thereto and outputs an output current signal, and a specific component A temperature detection circuit that detects the temperature and outputs a temperature signal is provided,
The control circuit includes a receiving unit having an RX terminal which is a high impedance input, and a communication UART composed of a transmitting unit having a TX terminal which is an output capable of changing to a low level, a high level or a high impedance. A module, the output voltage signal, the output current signal, the temperature signal, a mode setting signal for designating either the master mode or the slave mode, and a signal that can be externally input, and the target value of the output voltage The input / output is insulated by the control unit for controlling communication by the UART module and generating the control signal, and the first light emitting diode on the input side and the first phototransistor on the output side. Input / output is isolated by the first photocoupler, the second light emitting diode on the input side, and the second phototransistor on the output side A second photocoupler is provided which,
The one end of the first phototransistor is connected to the RX terminal, the one end of the second light emitting diode is connected to the TX terminal and the other end the UART of the other end and the second light emitting diode of the first phototransistor Connected to the module ground potential,
The UART module, the first light emitting diode end and said second phototransistor one end and an INF line connected to each other, and connecting the other ends of said second phototransistor of the first light emitting diode with each other External communication is possible through the GND line
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. A switching power supply that maintains the transmitter of the UART module at high impedance and generates the control signal so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the receiver. is there.

The invention according to claim 7 is a power supply system that uses a plurality of the switching power supply devices according to claim 1, the output terminals are connected in parallel or in series, and supplies power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and communication is possible through the INF line and the GND line. However, the mode setting signal designating the master mode is externally input to the control unit to become a master power source, and the switching power supply device other than the master power source is configured to send the mode setting signal designating the slave mode to the control unit. Is externally input to become a slave power supply,
In the master power supply, the UART module transmits the voltage setting signal and the output current signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit,
In the slave power supply, the UART module receives the two signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the two signals transmits its output current signal. Is a power supply system that determines the adjustment target value so as to approach the output current signal of the master power supply, and further generates the control signal so that the output voltage signal of the self approaches the adjustment target value.

The invention according to claim 8 is a power supply system that uses a plurality of the switching power supply devices according to claim 2, the output terminals are connected in parallel or in series, and supplies power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and a pull-up power supply having the GND line as a ground side is provided. Is pulled up to the power supply for pullup via the INF line and the GND line, and communication is possible through the INF line and the GND line. Externally input to the control unit to become a master power supply, the switching power supply device other than the master power supply is externally input to the control unit the mode setting signal designating the slave mode to become a slave power supply,
In the master power supply, the UART module transmits the voltage setting signal and the output current signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit,
In the slave power supply, the UART module receives the two signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the two signals transmits its output current signal. Is a power supply system that determines the adjustment target value so as to approach the output current signal of the master power supply, and further generates the control signal so that the output voltage signal of the self approaches the adjustment target value.

The invention according to claim 9 is a power supply system that uses a plurality of the switching power supply devices according to claim 3, the output terminals are connected in parallel or in series, and supplies power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and communication is possible through the INF line and the GND line. However, the mode setting signal designating the master mode is externally input to the control unit to become a master power source, and the switching power supply device other than the master power source is configured to send the mode setting signal designating the slave mode to the control unit. Is externally input to become a slave power supply,
In the master power supply, the UART module transmits the voltage setting signal and the temperature signal of the UART module from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the two signals transmitted from the master power supply through the RX terminal according to a command from the control unit, and the control unit that recognizes the two signals transmits the temperature signal of itself. In the power supply system, the adjustment target value is determined so as to approach the temperature signal of the master power supply, and the control signal is generated so that the output voltage signal of the master power supply approaches the adjustment target value.

A tenth aspect of the present invention is a power supply system that uses a plurality of the switching power supply units according to the fourth aspect, the output terminals are connected in parallel or in series, and supplies power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and a pull-up power supply having the GND line as a ground side is provided. Is pulled up to the power supply for pullup via the INF line and the GND line, and communication is possible through the INF line and the GND line. Externally input to the control unit to become a master power supply, the switching power supply device other than the master power supply is externally input to the control unit the mode setting signal designating the slave mode to become a slave power supply,
In the master power supply, the UART module transmits the voltage setting signal and the temperature signal of the UART module from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the two signals transmitted from the master power supply through the RX terminal according to a command from the control unit, and the control unit that recognizes the two signals transmits the temperature signal of itself. In the power supply system, the adjustment target value is determined so as to approach the temperature signal of the master power supply, and the control signal is generated so that the output voltage signal of the master power supply approaches the adjustment target value.

The invention according to claim 11 is a power supply system that uses a plurality of the switching power supply devices according to claim 5, the output terminals are connected in parallel or in series, and supplies power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and communication is possible through the INF line and the GND line. However, the mode setting signal designating the master mode is externally input to the control unit to become a master power source, and the switching power supply device other than the master power source is configured to send the mode setting signal designating the slave mode to the control unit. Is externally input to become a slave power supply,
In the master power supply, the UART module transmits the voltage setting signal, the output current signal, and the temperature signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the three signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the three signals transmits its output current signal. The adjustment target value is determined so that the temperature signal approaches the output current signal and the temperature signal of the master power supply, and the control signal is generated so that the output voltage signal of the self approaches the adjustment target value. It is a power system.

The invention according to claim 12 is a power supply system that uses a plurality of the switching power supply devices according to claim 6, the output terminals are connected in parallel or in series, and supplies power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and a pull-up power supply having the GND line as a ground side is provided. Is pulled up to the power supply for pullup via the INF line and the GND line, and communication is possible through the INF line and the GND line. Externally input to the control unit to become a master power supply, the switching power supply device other than the master power supply is externally input to the control unit the mode setting signal designating the slave mode to become a slave power supply,
In the master power supply, the UART module transmits the voltage setting signal, the output current signal, and the temperature signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the three signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the three signals transmits its output current signal. The adjustment target value is determined so that the temperature signal approaches the output current signal and the temperature signal of the master power supply, and the control signal is generated so that the output voltage signal of the self approaches the adjustment target value. It is a power system.

  The power supply system according to claim 7 or 8, wherein the communication frame transmitted by the master power supply is configured such that at least one frame includes communication information of a predetermined number of bits, and the communication information includes the voltage setting signal. Or, it is composed of data information that is the output current signal and identification information for 1 bit for identifying which signal the data information is, and the frequency that the data information is the output current signal is: It is preferable that the frequency is higher than the frequency of the voltage setting signal.

The power supply system according to claim 11 or 12, wherein the communication frame transmitted by the master power supply is configured such that at least one frame includes communication information of a predetermined number of bits, and the communication information includes the voltage setting signal. The output current signal or the temperature signal, and 2-bit identification information for identifying which signal the data information is, and the data information is the output current signal. The frequency is higher than the frequency of the voltage setting signal and the temperature signal,
The control unit of the slave power supply determines whether the data information is the output current signal based on the first bit of the identification information, and when determining that the data information is not the output current signal, When the second bit identifies whether the data information is the voltage setting signal or the temperature signal and determines that the data information is an output current signal, the second bit of the identification information is also a part of the bits constituting the data information It is preferable that the output current signal is recognized by assuming that the output current signal is recognized.

  Since the switching power supply apparatus according to the present invention performs balance control by highly intelligent digital arithmetic processing, the control circuit can be configured compactly with a smaller number of parts than analog control. In addition, the control circuit only needs to be capable of normal digital arithmetic processing and UART communication, and can be realized using an inexpensive general-purpose microcontroller. In addition, since there are fewer external connection terminals for parallel or series operation, the space for providing terminal pins or terminal blocks can be minimized.

  The power supply system of the present invention can accurately control the balance of the output current and temperature of each switching power supply device without separately providing a control device such as a system controller when the switching power supply devices are operated in parallel and in series. it can. In addition, it is not necessary to prepare two types of switching power supply devices for the master and the slave, and it is only necessary to prepare and wire a plurality of switching power supplies having the same specification.

  In addition, the number of wires between the switching power supply devices is small, and problems such as mutual interference due to capacitive coupling between communication lines can be easily avoided. In addition, the communication frame includes a predetermined number of bits of communication information included in one frame to increase the number of bits of data information by minimizing the number of bits of identification information, especially when the data information is an output current signal. Resolution can be increased.

It is a circuit diagram showing a power supply system of a first embodiment of this invention. It is a circuit diagram which shows the internal structure of n switching power supply devices used for the power supply system of 1st embodiment. It is an example of the overcurrent protection circuit omitted in FIG. It is a time chart (a) explaining the communication operation | movement which the power supply system of 1st embodiment performs, and the format (b) of a communication frame. It is a circuit diagram which shows the power supply system of 2nd embodiment of this invention. It is a circuit diagram which shows the internal structure of n switching power supply devices currently used for the power supply system of 2nd embodiment. 6 is an example of an overheat protection circuit omitted in FIG. 5. It is a time chart (a) explaining the communication operation | movement which the power supply system of 2nd embodiment performs, and the format (b) of a communication frame. It is a circuit diagram which shows the power supply system of 3rd embodiment of this invention. It is a circuit diagram which shows the internal structure of n switching power supply devices currently used for the power supply system of 3rd embodiment. It is a time chart explaining the communication operation | movement which the power supply system of 3rd embodiment performs. It is a circuit diagram which shows the switching power supply device of 4th embodiment.

  Hereinafter, a first embodiment of a switching power supply device and a power supply system using the same according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the power supply system 10 of this embodiment is a system that receives power from one input power supply 12 and outputs a predetermined voltage and current to one load 14. An arbitrary number n of switching power supply devices 16 are used. In the following, for convenience of explanation, n power supply units are represented by reference numerals 16 (1),..., 16 (k),. The numbers (1),..., (K),.

  As shown in FIG. 2, the switching power supply device 16 includes a power conversion circuit 18, a pulse generation circuit 20, an output voltage detection circuit 22, an output current detection circuit 24, and a control circuit 26.

  The power conversion circuit 18 includes a main switching element 28 that interrupts the input voltage Vi supplied between the input terminals + IN (k) and −IN (k), and the intermittent voltage applied to the primary winding to the secondary winding. And a rectifying / smoothing circuit 32 for converting the AC voltage of the secondary winding of the transformer 30 into the output voltage Vo, and a load connected to the output terminals + OUT (k) and -OUT (k) 14, the output voltage Vo (k) and the output current Io (k). The output voltage Vo (k) is determined by the on time and the off time during which the switching element 28 switches. Here, a single-ended forward type converter is illustrated as the power conversion circuit 18, but a different converter such as a flyback type, a bridge type, or a chopper type may be used.

  The pulse generation circuit 20 includes a triangular wave generation circuit 34 and a comparator 36, and generates a pulse voltage V36 for driving the main switching element 28. The triangular wave generation circuit 34 generates a triangular wave voltage V34 that repeats a saw-tooth voltage change at a constant frequency, and inputs it to the inverting input terminal of the comparator 36. A control signal Vd (k), which is an analog voltage output from the control circuit 26 described later, is input to the non-inverting input terminal of the comparator 36. The comparator 36 sets the pulse voltage V36 to a low level when the triangular wave voltage V34 is higher than the control signal Vd (k), and sets the pulse voltage V36 to a high level when the triangular wave voltage V34 is lower. Therefore, when the control signal Vd (k) becomes high, the high level time of the pulse voltage V36 becomes long, and the on-time of the main switching element becomes long. As a result, the on-time ratio increases, and the output voltage Vo (k) increases in proportion to it. On the contrary, when the control signal Vd (k) becomes low, the output voltage Vo (k) becomes low. The frequency of the triangular wave voltage V34 is the switching frequency of the main switching element 28.

  The output voltage detection circuit 22 detects the output voltage Vo or a voltage corresponding thereto, and outputs an output voltage signal Vo1 that is an analog voltage to the control circuit 26. Since the control circuit 26 to which the output voltage signal Vo1 is input has the ground potential GND (k) on the primary side of the transformer 30, the ground potential of the output voltage detection circuit 22 is also equal to the ground potential GND (k) of the control circuit 26. It is convenient to make it common. Therefore, as a configuration of the output voltage detection circuit 22, for example, a tertiary winding (not shown) is provided in the transformer 30, and an output voltage signal Vo1 substantially proportional to the output voltage Vo is obtained by rectifying and smoothing the voltage generated in the tertiary winding. Is preferable. As another method, an auxiliary winding insulated from the smoothing inductor of the rectifying / smoothing circuit 32 may be provided to obtain the output voltage signal Vo1 using the voltage generated in the auxiliary winding.

  The output current detection circuit 24 detects the output current Io or a current corresponding thereto, converts it to an analog voltage, and outputs it to the control circuit 26. As in the case of the output voltage detection circuit 22, the ground potential of the output current detection circuit 24 is also advantageously shared with the ground potential GND (k) of the control circuit 26. Therefore, the output current detection circuit 24 converts the switching current into a voltage with a resistor inserted at the connection point between the main switching element 28 and the ground potential GND (k), and observes the peak value to substantially reduce the output current Io. It is configured to acquire a proportional signal. Although omitted in FIG. 2, the switching power supply 16 is provided with a pulse-by-pulse overcurrent protection circuit 38 including a comparison circuit 38a and a latch circuit 38b as shown in FIG. ing. The overcurrent protection circuit 38 is a known circuit that forcibly turns off the main switching element 28 at the moment when the switching current exceeds a certain value and restricts the output current Io from becoming excessive. This type of protection circuit is provided in many switching power supply devices as a set with the output current detection circuit 24. Therefore, if there is an output current detection circuit 24 for overcurrent protection, there is no need to newly provide an output current detection circuit.

  The control circuit 26 includes a communication UART module 40 and a control unit 42 that controls the UART module 40 and outputs a control signal Vd (k) to the pulse generation circuit 20. The ground potential GND (k) of the control circuit 26 is the same potential as the negative input terminal -IN (k), and many parts of the control unit 42 and the UART module 40 are provided in one microcontroller. .

  The UART module 40 is a module for performing UART communication, and includes a receiver 40a having an RX (k) terminal that is a high impedance input, and an output that can be changed to a low level, a high level, or a high impedance. And a transmitter 40b having a TX (k) terminal. The RX (k) terminal and the TX (k) terminal are connected to each other to form an INF line 44 that communicates with the other switching power supply device 16 (k), and is drawn to the INF (k) terminal that is an external connection terminal. .

  The communication frame output from the TX (k) terminal by the transmission unit 40b is formatted as shown in FIG. 4B, and one frame includes a Start bit (1 bit), communication information (8 bits), a Parity bit (1 bit), and Stop. It consists of a total of 11 bits (1 bit). The communication information (8 bits) is composed of data information (7 bits) such as a detection signal and identification information (1 bit) for identifying the type of data information. The parity bit is an error check bit. The control unit 42 includes an error amplifier 46, a reference power supply 48, and a processing unit 50. In the error amplifier 46, the output voltage signal Vo1 is input to the inverting input terminal of the operational amplifier, and the voltage Vr (k) of the reference power supply 48 is input to the non-inverting input terminal. A control signal Vd (k) which is a voltage signal is generated and output to the pulse generation circuit 20. By this inversion amplification operation for the error, a negative feedback loop for the output voltage Vo is formed, and feedback control is performed so that the output voltage signal Vo1 (k) matches the voltage Vr (k). The voltage Vr (k) is either a self target value or an adjustment target value described later.

  The processing unit 50 receives a plurality of digital signals (a mode setting signal Vmo, a voltage setting signal Vtrm, an output current signal Io1, and a signal received by the receiving unit 40a), executes a program recorded in the memory, and executes a predetermined program. It is a block that performs digital arithmetic processing.

  The mode setting signal Vmo is a signal that is input from the MO (k) terminal, which is an external input terminal, to the processing unit 50, and is a signal that designates the operation mode of the processing unit 50 as either the master mode or the slave mode. is there. Here, the master mode is when the mode setting signal Vmo is at a high level, and the slave mode is when the mode setting signal Vmo is at a low level. The voltage setting signal Vtrm is a signal that is input to the processing unit 50 from a TRM (k) terminal that is an external input terminal, and is a signal that sets a target value of the output voltage Vo according to the type of the load 14. When the output voltage Vo is switched (for example, when 3.3V setting is changed to 2.0V setting), for example, the voltage applied to the TRM (k) terminal is changed and the voltage is applied via the A / D converter 52a. The setting signal Vtrm is changed. The output current signal Io1 is a signal obtained by digitally converting the peak value of the pulse voltage output from the output current detection circuit 24 by the A / D converter 52b. Here, the voltage setting signal Vtrm and the output current signal Io1 are configured with a sufficiently large number of bits (for example, 10 bits) in order to increase the detection resolution. The signal received by the receiving unit 40a will be described later.

The operation of the processing unit 50 is different between the master mode and the slave mode. Has been processing unit 50 specified as the master mode, to the transmission section 40b of the UART module 40, INF-line self-voltage setting signal Vtrm _{(k) 1} and the output current signal Io1 a _{(k) 1} from TX (k) terminal 44 to send through. Here, the voltage setting signal VTRM _{(k) 1} and the output current signal Io1 _{(k) 1} is a signal with rounded voltage setting signal VTRM of 10bit (k) and the output current signal Io1 a (k) to 7bit. Further, the processing unit 50 calculates a self target value Vr (k) determined from the voltage setting signal Vtrm (k), and sets the voltage of the reference power supply 48 to the self target value Vr (k). For example, if the relationship between the voltage setting signal Vtrm (k) and the self-target value Vr (k) is defined by a linear function, the self-target value Vr ( k) becomes a voltage of 1/2, and as a result, the output voltage Vo (or the output voltage signal Vo1) can be reduced to a voltage of 1/2. As described above, when the master mode is designated, the self output current signal Io1 (k) is not considered when the self target value Vr (k) is calculated.

  On the other hand, the processing unit 50 designated in the slave mode instructs the transmission unit 40b of the UART module 40 to stop the operation with the TX (k) terminal held at high impedance. Further, the adjustment target value Vr (k) determined by the signal received by the receiving unit 40a is calculated, and the voltage of the reference power supply 48 is set to the adjustment target value Vr (k). As described above, when the slave mode is designated, the self voltage setting signal Vtrm (k) is ignored. The adjustment target value Vr (k) will be described in detail in the operation description of the power supply system 10.

  The power supply system 10 includes the n switching power supply devices 16 (1) to 16 (n) described above, and ± IN (1) to ± IN (n) terminals are individually input power supplies as shown in FIG. 12 are connected to both ends, and a pair of ± OUT (1) to ± OUT (n) terminals are connected in parallel to a common load 14 so that n units can be operated in parallel.

  Furthermore, the INF (1) to INF (n) terminals of the switching power supply devices 16 (1) to 16 (n) are connected to each other by a single INF line 44. When the TX and RX terminals of each switching power supply device 16 are directly drawn out as external connection terminals, the TX terminal and the RX terminal are shortly connected outside each switching power supply device 16, and the connection points are connected to one INF. What is necessary is just to connect with the line 44. In addition, the ground potentials GND (1) to GND (n) of the control circuits 26 (1) to 26 (n) are also connected to the -IN (1) to -IN (n) terminals to connect the GND line 53 to the ground potential GND (1) to GND (n). It is connected.

  The MO (1) terminal of the switching power supply 16 (1) is connected to the midpoint of a series circuit of an input resistor 54 and a Zener diode 56 provided in parallel with the input power supply 12, and when the input voltage Vin is input, the MO (1) terminal is connected. (1) The terminal is held at a high level (the Zener voltage of the Zener diode 56), and the designation of the processing unit 50 of the control circuit 26 becomes the master mode. On the other hand, the MO (2) to MO (n) terminals of the switching power supply devices 16 (2) to 16 (k) are -IN (2) to -IN (n) terminals which are ground potentials via the pull-down resistor 58. Are always held at a low level, and all the designations of the processing units 50 of the control circuits 26 are in the slave mode. Thereby, the switching power supply device 16 (1) becomes the master power supply 16 (1), and all the other switching power supply devices 16 (2) to 16 (n) become the slave power supplies 16 (2) to 16 (n).

  The TRM (1) terminal of the master power supply 16 (1) is connected to the midpoint of the voltage dividing circuit that divides the Zener voltage of the Zener diode 56 by the resistor 60 and the variable resistor 62, and a predetermined DC voltage is input. . Therefore, by varying the resistance value of the variable resistor 62, the voltage setting signal Vtrm can be set to a predetermined value. On the other hand, the TRM (2) to TRM (n) terminals of the slave power supplies 16 (2) to 16 (n) are open. In the case of the slave power supply 16, since the processing unit 50 ignores its own voltage setting signal Vtrm, it is not necessary to input a signal.

  Next, the operation of the power supply system 10 will be described with reference to FIG. Here, in the time chart of FIG. 4A, the voltage logic of the INF line 44 is represented by “1” and “0”. “1” and “0” in this figure may be reversed depending on the setting of each UART module 40.

In the master power supply 16 (1), the processing unit 50 (1) calculates a self target value Vr (1) determined from its own voltage setting signal Vtrm (1), and the voltage of the reference power supply 48 is the self target value Vr (1). Set to Then, the on time and the off time of the main switching element 28 are set so that the output voltage signal Vo1 (1) approaches the self target value Vr (1). Furthermore, the master power supply 16 (1), the data information is a voltage setting signal VTRM _{(1) 1} or the output current signal Io1 _{(1) 1} a is a communication frame TX (1) sequentially transmitted from the terminal via the INF line 44, the slave The power supplies 16 (2) -16 (n) receive through the RX (2) -RX (n) terminals. As shown in FIG. 4B, each processing unit 50 of the slave power supplies 16 (2) to 16 (n) determines which signal the data information is based on whether the b0 bit of the identification information is “1” or “0”. Is identified.

The operation of the slave power supply 16 (2) will be described. First, the processing unit 50 (2) regards the received voltage setting signal Vtrm (1) ₁ as its own voltage setting signal Vtrm (2), and roughly adjusts the target value for adjustment. Vr (2) is calculated. Next, the received output current signal Io1 (1) ₁ and its own output current signal Io1 (2) are weighed so that the output current signal Io1 (2) approaches the output current signal Io1 (1) ₁ . Calculation for correcting the adjustment target value Vr (2) is performed. For example, if Io1 (2) <Io1 (1) ₁ , the correction target value Vr (2) is corrected to increase. If the correction amount is within the specified range, the voltage of the reference power supply 48 is set to the corrected adjustment target value Vr (2), and the output voltage signal Vo1 (2) approaches the adjustment target value Vr (2). Thus, the on time and off time of the main switching element 28 are set.

The process for calculating the adjustment target value Vr (2) is performed in two steps as described above. Considering balancing the output current signals Io1 (1) ₁ and Io1 (2), it is possible to omit the previous step and calculate the adjustment target value Vr (2) only by the subsequent step. By providing the previous step, the safety of the power supply system 10 can be further improved. For example, if a failure occurs in the output current detection circuit 24 of the slave power supply 16 (2) and the output current signal Io1 (2) cannot be detected, the correction amount becomes abnormally large and the on-time of the main switching element 28 is rapidly increased. This is dangerous because the output voltage Vo of the slave power supply 16 (2) cannot be controlled. However, in the slave power supply 16 (2), the difference (that is, the correction amount) between the adjustment target value Vr (2) calculated in the previous step and the adjustment target value Vr (2) corrected in the subsequent step exceeds the specified range. Then, it is determined that some abnormality has occurred, and the protection is activated by limiting the increase of the adjustment target value Vr (2) or stopping the switching operation.

  The operations of the other slave power supplies 16 (3) to 16 (n) are the same as those of the slave power supply 16 (2). In this way, the output current signals Io1 (1) to Io1 (n) of the master power supply 16 (1) and the slave power supplies 16 (2) to 16 (n) are balanced so as to approach each other.

As shown in FIG. 4 (a), data information master power source 16 (1) transmits sequentially, the output current signal Io1 _{(1) 1} in a frequency voltage setting signal VTRM ₍₁₎ higher than the frequency ₁ Here, it is set to 4 to 1. The voltage setting signal Vtrm (1) ₁ is a signal that is rarely changed after being set once by the variable resistor 62 outside the TRM (1) terminal, whereas the output current signal Io1 (1) ₁ is The signal changes frequently due to the balance control described above. Therefore, by increasing the frequency of the output current signal Io1 (1) ₁ , the responsiveness of the output current balance control can be increased.

Further, as shown in FIG. 4B, the output current signal Io1 (1) ₁ is composed of 7 bits. If the range of the output current Io is 0 to 100A, 100A ÷ 2 ⁷ = 0.78A. It has resolution and is sufficient for balance control of output current. On the other hand, if the output setting signal Vo1 (1) ₁ is also composed of 7 bits and the setting range of the output voltage Vo is set to 0 to 5V, the resolution becomes 5V ÷ 2 ⁷ = 39 mV, and the output voltage Not enough for control. However, each of the slave power supplies 16 (2) to 16 (n) determines the adjustment target values Vr (2) to Vr (n) by the above two steps, so that some error is generated in the previous step. Even if it does, since the said error part is masked by the correction | amendment (correction based on output current signal Io1 (1) ₁ ) by a subsequent step, it does not become a problem.

  As described above, since the switching power supply device 16 performs balance control by highly intelligent digital arithmetic processing, the control circuit 26 can be configured compactly with a smaller number of parts than analog control. Moreover, the control circuit 26 only needs to be capable of normal digital arithmetic processing and UART communication, and can be configured at low cost using a general-purpose microcontroller. Further, since the number of external connection terminals for parallel operation is small, the space for providing terminal pins or terminal blocks can be minimized.

Further, the power supply system 10 can accurately control the balance of the output current of each switching power supply device 16 without separately providing a control device (system controller or the like) other than the switching power supply device 16. In addition, it is not necessary to prepare two types of switching power supply devices for the master and the slave, and it is only necessary to prepare and wire a plurality of switching power supplies 16 having the same specification. Moreover, the number of wires between the switching power supply devices 16 is small, and problems such as mutual interference due to capacitive coupling between communication lines can be easily avoided.
Furthermore, since the communication frame is formatted as shown in FIG. 4B, the switching power supply system 10 can perform highly reliable communication. In the case of the I2C method described in the background art, transfer of one data is performed by dividing into an address information frame and a data information frame, and there is no error detection such as Parity in each frame. When a bit error occurs in the address information due to the influence of external noise or the like, there is a possibility that data may be transmitted to a switching power supply device that is different from the regular transmission destination, and there is a problem that communication reliability is very low. In contrast, in the case of the switching power supply system 10, transmission of a voltage setting signal or the like from the master power supply to the slave power supply is performed in units of one frame, and each frame is set by the parity bit provided in each frame. In this configuration, bit errors are detected. Therefore, when a bit error is detected, it is possible to reliably and easily prevent the slave power supply from malfunctioning by performing control of discarding the data information of the frame and waiting for the next transmission.

  Next, a second embodiment of the switching power supply device and the power supply system using the same according to the present invention will be described with reference to FIGS. Here, the same configurations as those of the power supply system 10 and the switching power supply device 16 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 5, the power supply system 64 of the second embodiment is a system that receives power from one input power supply 12 and outputs a predetermined voltage and current to one load 14. N switching power supply devices 66 are used.

  As shown in FIG. 6, the switching power supply device 66 includes a power conversion circuit 18, a pulse generation circuit 20, an output voltage detection circuit 22, an output current detection circuit 24, a temperature detection circuit 68, and a control circuit 70. The difference from the switching power supply device 16 of FIG. 2 is that a temperature detection circuit 68 is newly provided and a control circuit 70 is provided in place of the control circuit 26. Hereinafter, the configuration of the switching power supply device 66 will be described focusing on these portions.

  The temperature detection circuit 68 detects the temperature of a specific component inside the apparatus and outputs a signal to the control circuit 26. For specific parts, circuit elements and members that are susceptible to temperature stress are selected. For example, power semiconductors, ICs, and tantalum capacitors that have a significantly high failure rate at high temperatures are considered. It may be the temperature of the plate. The ground potential of the temperature detection circuit 68 is also common with the ground potential GND (k) of the control circuit 70 for the same reason as in the output voltage detection circuit 22 and the output current detection circuit 24. Here, the temperature detection circuit 68 divides the voltage of the DC power supply 68a, one end of which is connected to the ground potential GND (k), by the temperature detection thermistor 68b and the resistance 68c whose resistance value changes depending on the temperature, and outputs the voltage. It is configured to do. Although omitted in FIG. 6, the switching power supply 66 is provided with an overheat protection circuit 72 including a comparison circuit 72a and a latch circuit 72b, as shown in FIG. The overheat protection circuit 72 is a well-known circuit that fixes the main switching element 28 off when the temperature of the main switching element 28 exceeds a certain value and stops the power conversion operation. This type of circuit is set with the temperature detection 68. In many switching power supply apparatuses. Therefore, if there is a temperature detection circuit 68 for overheat protection, it is not necessary to provide a new temperature detection circuit.

  The control circuit 70 includes a communication UART module 40 and a new control unit 74 that controls the UART module 40 and outputs a control signal Vd (k) to the pulse generation circuit 20. The control unit 74 includes an error amplifier 46, a reference power supply 48, and a new processing unit 76. The error amplifier 46 and the reference voltage 48 are the same as those of the control circuit 26 in FIG.

  The processing unit 76 receives a plurality of digital signals (mode setting signal Vmo, voltage setting signal Vtrm, output current signal Io1, temperature signal Vtmp, and signal received by the receiving unit 40a), and executes a predetermined program recorded in the memory. It is a block that executes various processes and operations. That is, the temperature signal Vtmp that has not been handled by the processing unit 50 in FIG. 2 is also processed.

  The mode setting signal Vmo, the voltage setting signal Vtrm, the output current signal Io1, and the signal received by the receiving unit 40a are the same as described above. The temperature signal Vtmp is a signal obtained by digitally converting the analog voltage output from the temperature detection circuit 68 by the A / D converter 78. Similarly to the voltage setting signal Vtrm and the output current signal Io1, the temperature signal Vtmp is also configured with a sufficiently large number of bits (for example, 10 bits).

The operation of the processing unit 76 is different between the master mode and the slave mode, and the processing unit 76 designated in the master mode transmits its own voltage setting signal Vtrm to the transmission unit 40b of the UART module 40. _{(k) 1,} is instructed to transmit via INF line 44 output current signal Io1 _{(k) 1} and the temperature signal Vtmp a _{(k) 1} from TX (k) terminal. Here, the voltage setting signal VTRM _{(k) 1,} the output current signal Io1 _{(k) 1,} and the temperature signal Vtmp _{(k) 1,} the voltage setting signal VTRM of 10bit (k) and the output current signal Io1 6bit a (k) Alternatively, the signal is rounded to 7 bits. Further, the processing unit 76 calculates a self target value Vr (k) determined from the voltage setting signal Vtrm (k), and sets the voltage of the reference power supply 48 to the self target value Vr (k).

  On the other hand, the processing unit 76 designated in the slave mode instructs the transmission unit 40b of the UART module 40 to stop the operation with the TX (k) terminal held at high impedance. Further, the adjustment target value Vr (k) determined by the signal received by the receiving unit 40a is calculated, and the voltage of the reference power supply 48 is set to the adjustment target value Vr (k). As described above, when the slave mode is designated, the self voltage setting signal Vtrm (k) is ignored. The adjustment target value Vr (k) will be described in detail in the explanation of the operation of the power supply system 64.

  Although the configuration of the UART module 40 is the same as that described above, the format of the communication frame output from the transmission unit 40b from the TX (k) terminal has been changed from FIG. That is, as shown in FIG. 8B, one frame is composed of a total of 11 bits including a Start bit (1 bit), communication information (8 bits), a Parity bit (1 bit), and a Stop bit (1 bit). The communication information (8 bits) includes data information (6 bits) such as detection data and identification information (2 bits) for identifying the type of data information. The parity bit is an error check bit.

  The power supply system 64 includes n switching power supply devices 66 (1) to 66 (n), and ± IN (1) to ± IN (n) terminals are individually connected to the input power supply 12 as shown in FIG. A pair of ± OUT (1) to ± OUT (n) terminals are connected to each other in series with respect to a common load 14, and are configured to perform series operation with n units. Other connections of the INF (1) to INF (n) terminals, the MO (1) to MO (n) terminals, and the TRM (1) to TRM (n) terminals are the same as those of the power supply system 10 of FIG. Accordingly, in the power supply system 64, the switching power supply 66 (1) becomes the master power supply 66 (1), and all the other switching power supplies 66 (2) to 66 (n) are slave power supplies 66 (2) to 66 (n). )

Next, the operation of the power supply system 10 will be described with reference to FIG. The master power supply 66 (1) calculates the self target value Vr (1) determined by the treatment unit 76 (1) from its own voltage setting signal Vtrm (1), and the voltage of the reference power supply 48 is the self target value Vr (1). Set to Then, the ON time and OFF time of the main switching element 28 are set so that the output voltage signal Vo1 (1) approaches the self target value Vr (1). Furthermore, the master power supply 66 (1), the data information is a voltage setting signal VTRM _{(1) 1,} INF temperature signal Vtmp _{(1) 1} or the output current signal Io1 _{(1) 1} a is a communication frame from TX (1) terminal Transmit sequentially through line 44, and slave power supplies 66 (2) -66 (n) receive through RX (2) -RX (n) terminals. As shown in FIG. 8B, each of the processing units 76 of the slave power supplies 66 (2) to 66 (n) determines whether or not the data b0, which is the first bit of the identification information, is “1” or “0”. Whether the information is the output current signal Io1 (1) ₁ is identified. Here, when the b0 bit of the identification information is “1”, it is determined that the data information is not the output current signal Io1 (1), and the data information is further set to the voltage setting signal Vtrm (1) by the b2 bit of the identification information. ₁ or temperature signal Vtmp (1) ₁ is identified. On the other hand, when the b0 bit is “0”, it is determined that the data information is the output current signal Io1 (1) ₁ , and the b1 bit is also regarded as a part of the bits constituting the data information, so that the output current information Io1 ( 1) Recognize ₁

The operation of the slave power supply 66 (2) will be described. First, the processing unit 76 (2) uses the received voltage setting signal Vtrm (1) ₁ of the master power supply 66 (1) as its own voltage setting signal Vtrm (2). A rough adjustment target value Vr (2) is calculated. Next, the received output current signal Io1 (1) ₁ and its own output current signal Io1 (2) are weighed so that the output current signal Io1 (2) approaches the output current signal Io1 (1) ₁ . A calculation for correcting the adjustment target value Vr (2) is performed, and if the correction amount is within the specified range, the correction is validated. Here, since the system is a series operation system, there is no difference between the output current signal Io1 (1) and the output current signal Io1 (2), and the correction amount becomes substantially zero. Next, the received temperature signal Vtrm (1) _{1 of} the master power supply 66 (1) and its own temperature signal Vtrm (2) are weighed and the temperature signal Vtmp (2) approaches the temperature signal Vtmp (1) ₁ . In this way, the calculation for correcting the adjustment target value Vr (2) is further performed. For example, if the temperature of its own main switching element 28 is higher, the adjustment target value Vr (2) is corrected to be lowered. If the correction amount is within the specified range, the voltage of the reference power supply 48 is set to the corrected adjustment target value Vr (2), and the output voltage signal Vo1 (2) approaches the adjustment target value Vr (2). Thus, the on time and off time of the main switching element 28 are set.

  The process for calculating the adjustment target value Vr (2) is performed in three steps as described above. Thus, for example, even when a failure occurs in the output current detection circuit 24 or the temperature detection circuit 68, the adjustment target value Vr (2) is restricted from rising or the switching operation is stopped, so that the power supply system The safety of 64 is improved.

  The operation of the other slave power supplies 66 (3) to 66 (n) is the same as that of the slave power supply 66 (2). In this way, the output voltages Vo (2) to Vo (n) of the master power supply 66 (1) and the slave power supplies 16 (2) to 16 (n) increase or decrease, and the temperature signals Vtmp (2) to Vtmp (n) Is balanced to walk up to the master power supply.

As shown in FIG. 8B, the data information sequentially transmitted by the master power supply 66 (1) is configured such that the temperature signal Vtmp (1) ₁ is 6 bits and the temperature change width is 100 ° C. It has a resolution of 100 ° C. ÷ 2 ⁶ = 0.78 ° C., which is sufficient for temperature balance control. On the other hand, if the output setting signal Vo1 (1) ₁ is similarly composed of 6 bits and the setting range of the output voltage Vo is set to 0 to 5V, the resolution becomes 5V ÷ 2 ⁶ = 78 mV, and the output voltage Not enough for control. However, since each of the slave power supplies 66 (2) to 66 (n) determines the adjustment target values Vr (2) to Vr (n) by the above three steps, some error occurs in the previous step. However, the error is masked by the correction in the subsequent step (correction based on the temperature signal Vtmp (1) ₁ ).

  As described above, the power supply system 64 can accurately control the temperature balance of the internal components of the switching power supply devices 66 (1) to 66 (n) in addition to the operational effects of the power supply system 10. For example, when n switching power supply devices 66 are mounted in a narrow casing, even if the output current is balanced, the switching power supply devices 66 mounted so as to be surrounded by other switching power supply devices 66. The temperature of the specific part inside becomes high. Therefore, by performing the temperature balance control described above, it is possible to prevent temperature stress from concentrating on the specific switching power supply device 66 and to improve the reliability of the power supply system 64 as a whole.

  Also, a functional block corresponding to the overheat protection circuit 72 in FIG. 7 is provided in the control circuit 70 (microcontroller), and the overheat protection operation is performed using the temperature detection signal Vtrm, and the overheat protection circuit 72 is omitted. It is also possible to do.

Since the power supply system 64 is a system in which n switching power supply devices 66 are operated in series, the output currents Io (1) to Io (n) always coincide with each other, and there is no need to perform output current balance control. Therefore, the current detection circuit 24 and the A / D converter 52b are omitted from the configuration of the switching power supply device 66, and the processing unit 76 does not perform processing related to the output current signals Io1 (k) and Io1 (k) _1. Even when the system is configured using the power supply device, substantially the same operation and effect can be obtained.

In addition, it is possible to configure a power supply system for parallel operation using the switching power supply device 66, and it is possible to obtain the same operation effect as the above embodiment, and easily realize the output current balance control and the temperature balance control. can do. If the power supply system of parallel operation, the data information the master power source 66 (1) transmits sequentially, the output current signal Io1 _{(1) 1} in a frequency voltage setting signal VTRM _{(1) 1} 'or the temperature signal Vtmp (1) It is preferable that the frequency be higher than ₁ . For example, the master power source 66 (1), as shown in FIG. 8 (a), the output current signal Io1 _{(1) 1,} the voltage setting signal VTRM _{(1) 1,} the temperature signal Vtmp _{(1) 1} of the frequency, 4 It is good to set to one-to-one. The voltage setting signal Vtrm (1) is a signal that is rarely changed after being once set by the variable resistor 62 outside the TRM (1) terminal, and the temperature signal Vtmp (1) also changes relatively slowly. Although it is a signal, the output voltage signal Io1 (1) is a signal that can change frequently. Therefore, by increasing the frequency of the output current signal Io1 (1) ₁ , the responsiveness of the output current balance control can be improved.

  Next, a switching power supply device according to a third embodiment of the present invention and a power supply system using the same will be described with reference to FIGS. Here, the same configurations as those of the power supply system 10 and the switching power supply device 16 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 9, the power supply system 80 of the third embodiment is a system that receives power from one input power supply 12 and outputs a predetermined voltage and current to one load 14. N switching power supply devices 82 are used.

  As shown in FIG. 10, the switching power supply device 82 includes a power conversion circuit 18, a pulse generation circuit 20, an output voltage detection circuit 22, an output current detection circuit 24, a control circuit 26, and first and second photocouplers 84 and 86. It has. The difference from the switching power supply device 16 of FIG. 2 is that first and second photocouplers 84 and 86 are provided. Hereinafter, the configuration of the switching power supply device 82 will be described focusing on the two photocouplers 84 and 86.

  The input and output of the first photocoupler 84 are insulated by the first light emitting diode 84a on the input side and the first phototransistor 84b on the output side. Similarly, the input / output of the second photocoupler 86 is insulated between the second light emitting diode 86a on the input side and the second phototransistor 86b on the output side.

  The first phototransistor 84b is connected between the RX (k) terminal and the ground potential GND (k) of the control circuit 26, and the second light emitting diode 86a is connected to the TX (k) terminal and the ground potential GND (k). Connected between. Further, the anode of the first light emitting diode 84a and the collector of the second phototransistor 86b are connected to each other to form a new INF line 44, which is led out to the INF (k) terminal for external connection. Further, the cathode of the first light emitting diode 84a and the emitter of the second phototransistor 86b are connected to each other to form a new GND line 53, which is led out to a newly provided SG (k) terminal for external connection. Therefore, the switching power supply 82 (k) is insulated between the communication INF line 44 and the TX (k) and RX (k) terminals, and the communication GND line 53 and the ground potential GND (k) are A significant feature is that the connected -IN (k) terminals are insulated from each other.

  The power supply system 80 includes n switching power supply devices 82 (1) to 82 (n), and ± IN (1) to ± IN (n) terminals are individually connected to both ends of the input power supply 12 as shown in FIG. And a pair of ± OUT (1) to ± OUT (n) terminals are connected in parallel to the common load 14 and are configured to perform parallel operation with n units. Furthermore, noise filters 88 (1) to 88 (88) for reducing line noise are provided between the input power source 12 and the ± IN (1) to ± IN (n) terminals of the switching power supply devices 82 (1) to 82 (n). n) has been inserted. The noise filter 88 is a general filter circuit including, for example, a common mode inductor in which windings are arranged in the forward path and the return path, and a plurality of capacitors.

  The INF (1) to INF (n) terminals are connected to each other by a single INF line 44, and the SG (1) to SG (n) terminals are also connected to each other by a single GND line 53. A pull-up power supply 90 is provided between the INF line 44 and the GND line 53, and the INF line 44 is pulled up via a pull-up resistor 92. Connections of the MO (1) to MO (n) terminals and the TRM (1) to TRM (n) terminals are the same as those of the power supply system 10 of FIG. Therefore, in the power supply system 80, the switching power supply 82 (1) becomes the master power supply 82 (1), and all the other switching power supplies 82 (2) to 82 (n) are slave power supplies 82 (2) to 82 (n). )

  Next, the operation of the power supply system 80 will be described. The power supply system 80 operates basically in the same manner as the power supply system 10 of FIG. 1, and good output current balance control is performed. The difference is that when the logic of the communication frame transmitted from the master power source 82 (1) passes through the INF line 44 and the GND line 53, it is temporarily inverted.

  As shown in FIG. 11, the voltage logic of the TX (1) terminal, which is the output of the transmission unit 40b of the master power source 82 (1), is the same as the change shown in FIG. The voltage logic of the TX (1) terminal is inverted by passing through the first and second photocouplers 84 (1) and 86 (1), and the voltage logic of the INF line 44 is opposite to that of the TX (1) terminal. Become. The voltage logic of the INF line 44 is inverted by passing through the first photocouplers 84 (2) to 84 (n) and the second photocouplers 86 (2) to 86 (n), and RX (2) to The voltage logic at the RX (n) terminal is the same as the voltage logic at the TX (1) terminal.

  In the power supply system 80 using the switching power supply device 82, the system INF line 44 and the GND line 53 are insulated from other circuits, and between the master power supply 82 (1) and the slave power supplies 82 (2) to 82 (n). The noise filters 88 (1) to 88 (n) are not interposed in the communication path. Therefore, even when the noise filters 88 (1) to 88 (n) having high impedance are used, a communication failure does not occur due to this.

  When it is difficult to provide the pull-up power supply 90 and the pull-up resistor 92 separately from the switching power supply device 82 when configuring the power supply system 80, the internal (INF (k) terminal and A pull-up power supply 90 and a pull-up resistor 92 may be provided between the SG (k) terminal).

  Next, a fourth embodiment of the switching power supply device of the present invention will be described with reference to FIG. Here, the same components as those of the switching power supply device 16 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 12, the switching power supply device 94 of the fourth embodiment includes a power conversion circuit 18, a pulse generation circuit 96, an output voltage detection circuit 22, an output current detection circuit 24, and a control circuit 98. The difference from the switching power supply device 16 of FIG. 2 is that a pulse generation circuit 96 is provided instead of the pulse generation circuit 20 and a control circuit 98 is provided instead of the control circuit 26. Hereinafter, the configuration of the switching power supply device 94 will be described focusing on these portions.

  The pulse generation circuit 96 is a circuit that generates a pulse voltage V96 for driving the main switching element 28 based on a control signal D1 (k) that is a digital signal. For example, the pulse generation circuit 96 includes a clock, a counter, a pulse output circuit, and the like. A configured digital PWM is preferred.

  The pulse generation circuit 96 performs the following operation to generate a pulse voltage V96 whose cycle and duty are controlled. A clock is supplied to the digital PWM counter, and the counter counts the number of clocks. When the count value of the counter is reset to zero, the pulse voltage V96 output from the pulse output circuit becomes high level. Thereafter, counting continues with the pulse voltage V96 being at a high level. When the count value reaches the set value D1, the pulse voltage V96 changes to a low level, and when the count value reaches the set value D2, the counter is reset, The voltage V96 goes high. The pulse generation circuit 96 generates a pulse voltage V96 that repeats a high level and a low level by repeating the above operation. Accordingly, the cycle and duty of the pulse voltage V96 can be determined by the set values D1 and D2.

  In the pulse generation circuit 96, the set value D2 is fixed to a predetermined value set as default in order to make the switching cycle of the main switching element 28 constant. Then, a control signal D1 (k) output from the control circuit 98 described later is input as a set value D1, and the high level time of the pulse voltage V96, that is, the main switching element 28 is turned on by the control signal D1 (k). Time is set.

  The control circuit 98 includes a communication UART module 40 and a control unit 100 that controls the UART module 40 and outputs a control signal D1 (k) to the pulse generation circuit 96. The control unit 100 performs all operations similar to those performed by the control unit 50, the reference power supply 48, and the error amplifier 46 of FIG. 2 by digital arithmetic processing, and outputs a control signal D1 (k) that is a digital signal. In this case, since the output of the output voltage detection circuit 22 is an analog voltage signal, the output voltage signal Vo <b> 1 (k) converted into a digital signal by the A / D converter 102 needs to be input to the control unit 100.

  The switching power supply device 94 having the above configuration has the same function as the switching power supply device 16 of FIG. 2 and can obtain the same operational effects. Further, since most of the operations of the pulse generation circuit 96 and the control circuit 98 are performed by digital arithmetic processing, it can be configured by a microcontroller and a few electronic components. However, if control delay due to digital arithmetic processing becomes a problem, the pulse generator 20 and the control unit 42 that combine high-speed analog signal processing and digital arithmetic processing as in the switching power supply device 16 of FIG. It is good to choose one.

  The switching power supply device and the power supply system of the present invention are not limited to the above embodiment. For example, this switching power supply device can be used alone, and can be externally controlled through a TRM terminal or an INF terminal. The power conversion circuit may be either a DC-DC converter or an AC-DC converter, and may be an input / output insulation type or a non-insulation type. When a plurality of main switching elements are provided as in the bridge system, a plurality of outputs may be provided in the pulse generation circuit, and a corresponding pulse voltage may be output for each main switching element. Further, the switching frequency may be fixed or variable, and the type of control such as pulse width control, frequency control, phase shift control, etc. is not limited.

  Further, in the switching power supply device 82 shown in FIG. 10, the connection between the first phototransistor 84 b and the second light emitting diode 86 a can be changed according to the internal configuration of the UART module 40. For example, the first phototransistor has a collector connected to a positive terminal (not shown) of a DC power supply (power supply for driving the control circuit 26, etc.) and an emitter connected to an RX (k) terminal in accordance with the internal configuration of the receiver 40a. May be. The second light emitting diode may have an anode connected to a positive terminal of a DC power source (not shown) and a cathode connected to a TX (k) terminal in accordance with the internal configuration of the transmitter 40b. As described above, an appropriate connection method is appropriately selected in accordance with the internal configuration of the UART module to be used, and the same communication as described above can be performed among a plurality of UART modules.

  Moreover, this power supply system can realize any of parallel operation, series operation, and series-parallel operation. Further, whether to perform output current balance control or temperature balance control can be appropriately selected according to the system configuration. Further, the external connection circuit of the MO terminal and the TRM terminal of the master power supply may be changed to a configuration other than the configuration of the above embodiment. For example, in the configuration for specifying the mode of the control circuit using the MO terminal, the connection of the MO terminal is opened or shorted instead of the configuration of the resistor 54 and the Zener diode 56 shown in FIG. By doing so, it may be configured to designate a master or a slave. The analog voltage applied to the MO terminal is input to the control circuit via the A / D converter, and the control circuit makes a determination based on the voltage value and designates the master or slave. Is also possible. The external connection circuit of the TRM terminal may be any circuit that can apply a stable analog voltage to the TRM terminal, and is limited to the configuration of the Zener diode 56, the resistors 54 and 60, and the variable resistor 62 shown in FIG. Is not to be done.

  The configuration of the bits of the communication frame described with reference to FIGS. 4 and 8 is an example of how to allocate the total number of bits included in a specific UART module, and depends on the resolution required for data information, the performance of the UART module, and the like. Can be changed. In the above example, the format of the communication frame is configured such that the start bit is 1 bit, the communication information is 8 bits, the parity bit is 1 bit, and the stop bit is 1 bit. However, depending on the type of UART module used, the communication information 7 bits or 9 bits may be selected, and 1.5 bits or 2 bits may be selected as the Stop bit. For example, if 7 bits are selected as communication information, the identification information is 1 bit or 2 bits, so the data information is 6 bits or 5 bits. On the other hand, if 9 bits are selected as the communication information, the identification information is 1 bit or 2 bits, so the data information is 8 bits or 7 bits.

10, 64, 80 Power supply system 16, 66, 82, 94 Switching power supply 18 Power conversion circuit 20, 96 Pulse generation circuit 22 Output voltage detection circuit 24 Output current detection circuit 26, 70, 98 Control circuit 28 Main switching element 32 Rectification Smoothing circuit 40 UART module 40a Receiver 40b Transmitters 42, 74, 100 Controller 44 INF line 53 GND line 68 Temperature detection circuit 84 First photocoupler 84a First light-emitting diode 84b First phototransistor 86 Second photocoupler 86a First Two light emitting diodes 86b Second phototransistor 88 Noise filter 90 Pull-up power supply 92 Pull-up resistor

Claims (14)

An input voltage supplied to the input terminal is converted into a DC voltage by a switching operation of the main switching element, and an output voltage and an output current are supplied to a load connected to the output terminal, and the main switching element is turned on. In a switching power supply comprising: a control circuit that generates a control signal that defines a time and an off time; and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal.
An output voltage detection circuit for detecting the output voltage or a voltage corresponding thereto and outputting an output voltage signal; and an output current detection circuit for detecting the output current or a current corresponding thereto and outputting an output current signal;
The control circuit includes a receiving unit having an RX terminal which is a high impedance input, and a communication UART composed of a transmitting unit having a TX terminal which is an output capable of changing to a low level, a high level or a high impedance. Module,
The output voltage signal, the output current signal, a mode setting signal for designating one of the master mode and the slave mode, and a voltage setting signal for determining a target value of the output voltage that can be externally input. And a control unit for controlling communication by the UART module and generating the control signal,
The UART module can perform external communication through an INF line that connects the RX terminal and the TX terminal to each other and a GND line that is a ground potential of the UART module.
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. In this case, the transmission unit of the UART module is held at a high impedance, and the control signal is generated so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the reception unit. Switching power supply. An input voltage supplied to the input terminal is converted into a DC voltage by a switching operation of the main switching element, and an output voltage and an output current are supplied to a load connected to the output terminal, and the main switching element is turned on. In a switching power supply comprising: a control circuit that generates a control signal that defines a time and an off time; and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal.
An output voltage detection circuit for detecting the output voltage or a voltage corresponding thereto and outputting an output voltage signal; and an output current detection circuit for detecting the output current or a current corresponding thereto and outputting an output current signal;
The control circuit includes a receiving unit having an RX terminal which is a high impedance input, and a communication UART composed of a transmitting unit having a TX terminal which is an output capable of changing to a low level, a high level or a high impedance. A voltage setting for determining a target value of the output voltage, the module, the output voltage signal, the output current signal, a mode setting signal for designating either the master mode or the slave mode, and a signal capable of external input A control unit that receives a signal, controls communication by the UART module and generates the control signal, and a first photocoupler whose input and output are insulated by a first light emitting diode on the input side and a first phototransistor on the output side And a second photodiode whose input and output are insulated by a second light emitting diode on the input side and a second phototransistor on the output side. Coupler and is provided,
One end of the first phototransistor is connected to the RX terminal, one end of the second light emitting diode is connected to the TX terminal, and the other end of the first phototransistor and the other end of the second light emitting diode are connected to the UART. Connected to the module ground potential,
The UART module has an INF line connecting one end of the first light emitting diode and one end of the second phototransistor, and connects the other end of the first light emitting diode and the other end of the second phototransistor. External communication is possible through the GND line
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. In this case, the transmission unit of the UART module is held at a high impedance, and the control signal is generated so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the reception unit. Switching power supply. An input voltage supplied to the input terminal is converted into a DC voltage by a switching operation of the main switching element, and an output voltage and an output current are supplied to a load connected to the output terminal, and the main switching element is turned on. In a switching power supply comprising: a control circuit that generates a control signal that defines a time and an off time; and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal.
An output voltage detection circuit that detects the output voltage or a voltage corresponding to the output voltage and outputs an output voltage signal, and a temperature detection circuit that detects the temperature of a specific component and outputs a temperature signal are provided,
The control circuit includes a receiving unit having an RX terminal that is a high impedance input and a transmitting unit having a TX terminal that is an output that can be changed to a low level, a high level, or a high impedance. A UART module;
Upon receiving the output voltage signal, the temperature signal, a mode setting signal for designating either the master mode or the slave mode, and a voltage setting signal that can be externally input and determines a target value of the output voltage A control unit for controlling communication by the UART module and generating the control signal,
The UART module can perform external communication through an INF line that connects the RX terminal and the TX terminal to each other and a GND line that is a ground potential of the UART module.
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. In this case, the transmission unit of the UART module is held at a high impedance, and the control signal is generated so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the reception unit. Switching power supply. An input voltage supplied to the input terminal is converted into a DC voltage by a switching operation of the main switching element, and an output voltage and an output current are supplied to a load connected to the output terminal, and the main switching element is turned on. In a switching power supply comprising: a control circuit that generates a control signal that defines a time and an off time; and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal.
An output voltage detection circuit that detects the output voltage or a voltage corresponding to the output voltage and outputs an output voltage signal, and a temperature detection circuit that detects the temperature of a specific component and outputs a temperature signal are provided,
The control circuit includes a receiving unit having an RX terminal that is a high impedance input and a transmitting unit having a TX terminal that is an output that can be changed to a low level, a high level, or a high impedance. UART module, the output voltage signal, the temperature signal, a mode setting signal for designating either the master mode or the slave mode, and a signal that can be externally input, and a voltage setting that determines the target value of the output voltage A control unit that receives a signal, controls communication by the UART module and generates the control signal, and a first photocoupler whose input and output are insulated by a first light emitting diode on the input side and a first phototransistor on the output side And a second photocathode whose input and output are insulated by a second light emitting diode on the input side and a second phototransistor on the output side. La and is provided,
The one end of the first phototransistor is connected to the RX terminal, the one end of the second light emitting diode is connected to the TX terminal and the other end the UART of the other end and the second light emitting diode of the first phototransistor Connected to the module ground potential,
The UART module, the first light emitting diode end and said second phototransistor one end and an INF line connected to each other, and connecting the other ends of said second phototransistor of the first light emitting diode with each other External communication is possible through the GND line
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. In this case, the transmission unit of the UART module is held at a high impedance, and the control signal is generated so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the reception unit. switching power supply that.   A temperature detection circuit for detecting a temperature of a specific component and outputting a temperature signal is provided, and the control circuit further includes the output voltage signal, the output current signal, the temperature signal, the mode setting signal, and the voltage setting. The switching power supply apparatus according to claim 1, further comprising a control unit that receives a signal and controls communication by the UART module and generates the control signal. An input voltage supplied to the input terminal is converted into a DC voltage by a switching operation of the main switching element, and an output voltage and an output current are supplied to a load connected to the output terminal, and the main switching element is turned on. In a switching power supply comprising: a control circuit that generates a control signal that defines a time and an off time; and a pulse generation circuit that generates a pulse voltage for driving the main switching element based on the control signal.
An output voltage detection circuit that detects the output voltage or a voltage corresponding thereto and outputs an output voltage signal, an output current detection circuit that detects the output current or a current corresponding thereto and outputs an output current signal, and a specific component A temperature detection circuit that detects the temperature and outputs a temperature signal is provided,
The control circuit includes a receiving unit having an RX terminal which is a high impedance input, and a communication UART composed of a transmitting unit having a TX terminal which is an output capable of changing to a low level, a high level or a high impedance. A module, the output voltage signal, the output current signal, the temperature signal, a mode setting signal for designating either the master mode or the slave mode, and a signal that can be externally input, and the target value of the output voltage The input / output is insulated by the control unit for controlling communication by the UART module and generating the control signal, and the first light emitting diode on the input side and the first phototransistor on the output side. Input / output is isolated by the first photocoupler, the second light emitting diode on the input side, and the second phototransistor on the output side A second photocoupler is provided which,
The one end of the first phototransistor is connected to the RX terminal, the one end of the second light emitting diode is connected to the TX terminal and the other end the UART of the other end and the second light emitting diode of the first phototransistor Connected to the module ground potential,
The UART module, the first light emitting diode end and said second phototransistor one end and an INF line connected to each other, and connecting the other ends of said second phototransistor of the first light emitting diode with each other External communication is possible through the GND line
When the master mode is designated, the control unit generates the control signal so that the output voltage signal of the self approaches a self target value determined by the voltage setting signal of the self, and the slave mode is designated. In this case, the transmission unit of the UART module is held at a high impedance, and the control signal is generated so that the output voltage signal of the UART module approaches an adjustment target value determined by a signal received by the reception unit. switching power supply that. A power supply system using a plurality of the switching power supply devices according to claim 1, wherein the output terminals are connected in parallel or in series with each other, and supply power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and communication is possible through the INF line and the GND line.
Any one of the switching power supply units inputs the mode setting signal designating the master mode to the control unit as a master power supply, and the switching power supply apparatus other than the master power supply designates the slave mode. The mode setting signal is externally input to the control unit and becomes a slave power supply.
In the master power supply, the UART module transmits the voltage setting signal and the output current signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit,
In the slave power supply, the UART module receives the two signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the two signals transmits its output current signal. The adjustment target value is determined so as to approach the output current signal of the master power supply, and the control signal is generated so that the output voltage signal of the master power supply approaches the adjustment target value. . A plurality of the switching power supply devices according to claim 2, wherein the output terminals are connected in parallel or in series with each other, and supply power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and a pull-up power supply having the GND line as a ground side is provided. Is pulled up to the power supply for pullup via the INF, and can communicate through the INF line and the GND line,
Any one of the switching power supply units inputs the mode setting signal designating the master mode to the control unit as a master power supply, and the switching power supply apparatus other than the master power supply designates the slave mode. The mode setting signal is externally input to the control unit and becomes a slave power supply.
In the master power supply, the UART module transmits the voltage setting signal and the output current signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit,
In the slave power supply, the UART module receives the two signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the two signals transmits its output current signal. The adjustment target value is determined so as to approach the output current signal of the master power supply, and the control signal is generated so that the output voltage signal of the master power supply approaches the adjustment target value. . A plurality of the switching power supply devices according to claim 3, wherein the output terminals are connected to each other in parallel or in series, and supply power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and communication is possible through the INF line and the GND line.
Any one of the switching power supply units inputs the mode setting signal designating the master mode to the control unit as a master power supply, and the switching power supply apparatus other than the master power supply designates the slave mode. The mode setting signal is externally input to the control unit and becomes a slave power supply.
In the master power supply, the UART module transmits the voltage setting signal and the temperature signal of the UART module from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the two signals transmitted from the master power supply through the RX terminal according to a command from the control unit, and the control unit that recognizes the two signals transmits the temperature signal of itself. The power supply system is characterized in that the adjustment target value is determined so as to approach the temperature signal of the master power supply, and further, the control signal is generated so that the output voltage signal of the master power supply approaches the adjustment target value. A plurality of the switching power supply devices according to claim 4, wherein the output terminals are connected in parallel or in series with each other, and supply power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and a pull-up power supply having the GND line as a ground side is provided. Is pulled up to the power supply for pullup via the INF, and can communicate through the INF line and the GND line,
Any one of the switching power supply units inputs the mode setting signal designating the master mode to the control unit as a master power supply, and the switching power supply apparatus other than the master power supply designates the slave mode. The mode setting signal is externally input to the control unit and becomes a slave power supply.
In the master power supply, the UART module transmits the voltage setting signal and the temperature signal of the UART module from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the two signals transmitted from the master power supply through the RX terminal according to a command from the control unit, and the control unit that recognizes the two signals transmits the temperature signal of itself. The power supply system is characterized in that the adjustment target value is determined so as to approach the temperature signal of the master power supply, and further, the control signal is generated so that the output voltage signal of the master power supply approaches the adjustment target value. A power supply system using a plurality of the switching power supply devices according to claim 5, wherein the output terminals are connected in parallel or in series with each other, and supply power to the common load,
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and communication is possible through the INF line and the GND line.
Any one of the switching power supply units inputs the mode setting signal designating the master mode to the control unit as a master power supply, and the switching power supply apparatus other than the master power supply designates the slave mode. The mode setting signal is externally input to the control unit and becomes a slave power supply.
In the master power supply, the UART module transmits the voltage setting signal, the output current signal, and the temperature signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the three signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the three signals transmits its output current signal. The adjustment target value is determined so that the temperature signal approaches the output current signal and the temperature signal of the master power supply, and the control signal is generated so that the output voltage signal of the self approaches the adjustment target value. A power supply system characterized by A power supply system using a plurality of the switching power supply devices according to claim 6, wherein the output ends are connected in parallel or in series with each other, and supply power to the common load.
In the plurality of switching power supply devices, the INF lines are connected to each other, the GND lines are connected to each other, and a pull-up power supply having the GND line as a ground side is provided. Is pulled up to the power supply for pullup via the INF, and can communicate through the INF line and the GND line,
Any one of the switching power supply units inputs the mode setting signal designating the master mode to the control unit as a master power supply, and the switching power supply apparatus other than the master power supply designates the slave mode. The mode setting signal is externally input to the control unit and becomes a slave power supply.
In the master power supply, the UART module transmits the voltage setting signal, the output current signal, and the temperature signal from the TX terminal to the slave power supply through the INF line according to a command from the control unit.
In the slave power supply, the UART module receives the three signals transmitted by the master power supply in response to a command from the control unit through the RX terminal, and the control unit that recognizes the three signals transmits its output current signal. The adjustment target value is determined so that the temperature signal approaches the output current signal and the temperature signal of the master power supply, and the control signal is generated so that the output voltage signal of the self approaches the adjustment target value. A power supply system characterized by   The communication frame transmitted by the master power supply is configured to include communication information of a predetermined number of bits in at least one frame, and the communication information includes the data information that is the voltage setting signal or the output current signal, The frequency of the data information being the output current signal is higher than the frequency of being the voltage setting signal, comprising identification information for one bit for identifying which signal the data information is. The power supply system according to 7 or 8. The communication frame transmitted by the master power supply is configured such that at least one frame includes communication information of a predetermined number of bits, and the communication information is data that is the voltage setting signal, the output current signal, or the temperature signal. Information and 2-bit identification information for identifying which signal the data information is, and the frequency at which the data information is the output current signal depends on the voltage setting signal and the temperature signal. Higher than the frequency of
The control unit of the slave power supply determines whether the data information is the output current signal based on the first bit of the identification information, and when determining that the data information is not the output current signal, When the second bit identifies whether the data information is the voltage setting signal or the temperature signal and determines that the data information is an output current signal, the second bit of the identification information is also a part of the bits constituting the data information The power supply system according to claim 11 or 12, wherein the output current signal is recognized as being

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