JP6174525B2 - Switching power supply - Google Patents

Description

  The present invention relates to a switching power supply device having a function of communicating with an external device.

  2. Description of the Related Art Conventionally, a switching power supply apparatus in which a digital processor is provided in a control circuit for digitally controlling a power conversion operation and communication between the digital processor and an external device is enabled has been put into practical use. When this type of switching power supply device is used, for example, the power supply systems 1 and 2 as shown in FIGS. 6A and 6B can be configured.

  As illustrated in FIG. 6A, the power supply system 1 includes a conventional switching power supply device 3, a load 4, and an external device 5. The switching power supply device 3 is a device that receives an input voltage Vi, converts it into a main output voltage Vo and an auxiliary output voltage Vr, and outputs it. Although an internal circuit is not shown, for example, one input winding and 2 A converter transformer having two output windings is provided, and a main switching element connected in series to the input windings applies an intermittent voltage to the input windings by interrupting the input voltage Vi, and is generated in two output windings. The AC voltage is rectified and smoothed to output voltages Vo and Vr. The load 4 is an electronic device or the like that operates using the main output voltage Vo as an operation voltage. The external device 5 is a device that communicates with the switching power supply device 2 and the load 4 through the communication bus 6 to monitor the operation state and change the operation state. A configuration similar to the power supply system 1 is disclosed, for example, in FIGS.

  The power supply system 2 is obtained by changing a part of the configuration of the power supply system 1. As shown in FIG. 6B, a conventional switching power supply device 7 is used instead of the switching power supply device 3, and a new auxiliary power supply system is provided. A power supply device 8 is added. The switching power supply device 7 outputs only the main output voltage Vo that is an operation voltage of the load 4, and the auxiliary power supply device 8 generates and outputs an auxiliary output voltage Vr that is an operation voltage of the external device 5. A configuration similar to the power supply system 2 is disclosed in FIG.

In recent years, various standards have been established for standardizing specifications of switching power supply devices having a communication function. For example, PMBus (Power Management) established by SMIF (System Management Interface forum), an organization in which multiple power supply manufacturers participated
Bus (I2C) (Inter Integrated Circuit) power management bus protocol called Bus), and terminal arrangement standards for power supply units established by DSA (Distributed-power Open Standard Alliance), a power module standardization organization. For this reason, there have been increasing cases in which a power supply system designer or the like is required to develop a switching power supply device that complies with these standards.

Japanese Patent Laid-Open No. 2004-3776

  However, in the power supply system 1 using the conventional switching power supply device 3, when the input voltage Vi is input to the switching power supply device 3, the main output voltage Vo and the auxiliary output voltage Vr rise almost simultaneously, and the external device 5 and the load 4 However, since the start timings of the switching power supply device 3 and the load 4 cannot be controlled by the external device 5, there is a problem in that the external device 5 cannot control the startup characteristics. Further, as described in Patent Document 1, it is possible to vary or stop only one voltage because the main output voltage Vo and the auxiliary output voltage Vr are generated by one power conversion circuit. There is also the problem that it is difficult. In addition, the configuration of the switching power supply device 3 cannot conform to the DOSA terminal layout standard.

  On the other hand, in the case of the power supply system 2 using the conventional switching power supply device 7, the above operational problems can be solved. It is also possible to make the switching power supply device 7 comply with the PMBus standard or the DOSA terminal layout standard. However, since the power supply system 2 must add the auxiliary power supply device 8 separately from the switching power supply device 7, the configuration of the entire system is more complicated than the power supply system 1.

  The present invention has been made in view of the above-described background art, and provides a switching power supply device that can easily select or change specifications conforming to various standards and individual specifications similar thereto in the production process of the power supply apparatus. The purpose is to provide.

The present invention provides a first power converter that converts an input voltage into a main output voltage and outputs the first power converter, a first converter provided with a first control circuit that controls the operation of the first power converter, and the first converter A serial communication module provided in one control circuit, a second power conversion unit that converts the input voltage into an auxiliary output voltage and outputs it, and a second control circuit that controls the operation of the second power conversion unit are provided The second converter and a plurality of external connection terminals connected to the other mounting board,
The plurality of external connection terminals include a pair of input terminals to which the input voltage is externally input at both ends,
A pair of main output terminals that output the main output voltage from both ends, and a serial communication terminal that is connected to an external device and enables communication between the serial communication module and the external device;
An external ground terminal that is connected to the ground of the external device, a main address setting terminal that is an external connection terminal for giving an address for serial communication to the first control circuit, and a function variable whose function setting can be switched. Terminal and
The function of the function variable terminal is set by built-in switching means, and the switching means provides the function variable terminal with the address of the first control circuit in cooperation with the main address setting terminal. A setting to be an auxiliary address setting terminal that is an external connection terminal and a setting to make the function variable terminal an auxiliary output terminal that outputs the auxiliary output voltage as an operation voltage of the external device are switchable. It is a switching power supply device.

  The serial communication module is an I2C communication module, and a terminal for clock transmission / reception and a terminal for data transmission / reception are provided as the serial communication terminals.

  Each internal circuit of the first and second converters is composed of an input side circuit and an output side circuit that are insulated from each other, the serial communication module, the pair of main output terminals, the serial communication terminals, and the external The ground terminal, the main address setting terminal, and the function variable terminal are provided in the output side circuit of the first or second converter. In this case, the second power converter converts the input voltage into the auxiliary output voltage and the control voltage and outputs the output voltage, and the control voltage is provided in the output side circuit in the first control circuit. It is preferable to be used as an operating voltage for the portion that is provided.

  Since the switching power supply device of the present invention includes a serial communication module and an external connection terminal necessary for communication using the same, the communication protocol can be made to comply with various serial communication standards (such as PMBus). Furthermore, by switching the setting of the switching means, specifications conforming to the terminal arrangement standards such as DOSA and individual specifications similar to these can be easily selected or changed in the production process of the power supply device. Regardless of the specification of the order, the specified product can be quickly produced and shipped.

It is the front view (a) which shows the external appearance of one Embodiment of the switching power supply device of this invention, a bottom view (b), and the figure (c) which shows the arrangement | sequence of an external connection terminal. It is a circuit block diagram which shows the internal structure of the switching power supply device of this embodiment. FIG. 3 is a diagram (a), (b), and (c) illustrating an example of the switching unit in FIG. 2. It is a circuit block diagram which shows an example of the power supply system comprised using the switching power supply device of this embodiment. It is a circuit block diagram which shows the other example of the power supply system comprised using the switching power supply device of this embodiment. It is a circuit block diagram (a), (b) which shows the example of the power supply system comprised using the conventional switching power supply device.

  Hereinafter, an embodiment of a switching power supply device of the present invention will be described with reference to FIGS. In the switching power supply device 10 of this embodiment, as shown in FIG. 1, a plurality of circuit elements 14 constituting an internal circuit are mounted on both surfaces of a circuit board 12 that is a multilayer board, and on the bottom side of the circuit board 12, This is a 1/4 brick size power supply device in which a plurality of external connection terminals 18 for connection to the counterpart mounting substrate 16 are provided. The external connection terminal 18 is a metal pin, for example, and is inserted into the through hole 16a of the mounting substrate 16 and soldered.

  The plurality of external connection terminals 18 are a P1 (+ Vi) terminal to a P15 (Addr0) terminal, as shown in FIG. The layout of each terminal can conform to the standard of DOSA terminal arrangement by setting the function of the P14 (Addr1 / Vr) terminal, which is a function variable terminal, to the P14 (Addr1) terminal. Details will be described later.

  As shown in FIG. 2, the switching power supply device 10 includes an input / output insulation type first converter 20, an input / output insulation type second converter 22, and a switching unit 24. It is pulled out to the connection terminal 18.

  The first converter 20 includes a first power converter 26 that converts the input voltage Vi into the main output voltage Vo and outputs the converted voltage. The main output voltage Vo is a voltage for operating the load. The first power conversion unit 26 applies the intermittent voltage to the input winding 30a of the transformer 30 by intermittently inputting the input voltage Vi by the switching element 28, and converts the AC voltage generated in the output winding 30b to the first rectifying and smoothing circuit 32. The main output voltage Vo is generated by rectifying and smoothing.

  The operation of the first power converter 26 is controlled by the first control circuit 34. The first control circuit 34 detects the main output voltage Vo by the first voltage detection circuit 36, and the first control unit 38 turns on and off the switching element 28 so that the main output voltage Vo is maintained at the target value. The time is determined, and the information is transmitted to the first drive circuit 42 through the isolator 40, and the first drive circuit 42 drives the switching element 28. The first control unit 38 is a highly intelligent multi-functional circuit block composed of a digital processor. For example, the on-time of the switching element 28 is compulsorily controlled in addition to the control for maintaining the main output voltage Vo at the target value. It is possible to perform control (overcurrent protection, overvoltage protection) for shortening or stopping the on / off operation, on / off start timing of the switching element 28 at start-up, control of the maximum on time (soft start), and the like. The first control unit 38 is provided with an I2C module 38a, which is a serial communication module, and can perform I2C communication with an external device. The communication function of the first control unit 38 will be described later.

  In the first converter 20, an internal circuit is separated into an input side circuit 44 and an output side circuit 46, and is insulated from each other via a transformer 30 and an isolator 40. That is, the switching element 28 and the first drive circuit 42 are provided in the input side circuit 44, and the first rectification smoothing circuit 32, the first voltage detection circuit 36, and the first control unit 38 are provided in the output side circuit 46. Yes.

  The second converter 22 includes a second power converter 48 that generates and outputs an auxiliary output voltage Vr and a control voltage Vs (> Vr) from the input voltage Vi. The second power converter 48 applies the intermittent voltage to the input winding 52a of the transformer 52 by intermittently inputting the input voltage Vi by the switching element 50, and converts the AC voltage generated in the output winding 52b into the second rectifying and smoothing circuit 54. The control voltage Vs is generated by rectifying and smoothing. The control voltage Vs is used as an operation voltage for the first control unit 38 and the first voltage detection circuit 36 provided in the output side circuit 46 of the first converter 20. Further, a step-down regulator 56 is provided after the second rectifying / smoothing circuit 32 to generate the auxiliary output voltage Vr. The auxiliary output voltage Vr is a voltage used as an operating voltage for an external device.

  The configuration of the subsequent stage of the second rectifying / smoothing circuit 32 is changed depending on the levels of the voltages Vr and Vs. For example, when Vr = Vs, the regulator 56 can be omitted. When Vr> Vs, the output voltage of the second rectifying / smoothing circuit 54 may be the auxiliary output voltage Vr, and the auxiliary output voltage Vr may be stepped down by the regulator 56 to generate the control voltage Vs.

  The operation of the second power converter 48 is controlled by the second control circuit 58. The second control circuit 58 detects the control voltage Vs (or auxiliary output voltage Vr) with the second voltage detection circuit 60, and the information is transmitted to the second control unit 64 through the isolator 62. The on-time and off-time of the switching element 50 are determined so that the control voltage Vs (or auxiliary output voltage Vr) is maintained at the target value, and the second drive circuit 66 drives the switching element 66.

  The second converter 22 has an internal circuit separated into an input side circuit 68 and an output side circuit 70 and is insulated from each other via a transformer 52 and an isolator 62. That is, the switching element 50, the second control unit 64, and the second drive circuit 68 are provided in the input side circuit 68, and the second rectification smoothing circuit 54, the second voltage detection circuit 60, and the regulator are provided in the output side circuit 70. 56 is provided.

  In order to perform I2C communication, a communication address must be assigned to the first control circuit 34. The first control unit 38 has an Addr0 pin and an Addr1 pin for address setting, and an address is given according to a voltage value (analog value) of each pin when an external resistor is connected to each terminal. For example, if the voltage range of two pins is divided into 8 parts, 8 × 8 = 64 addresses can be assigned. If the voltage of Addr1 pin is ignored, eight different addresses can be assigned by the voltage of Addr0 pin.

  The plurality of external connection terminals 18 includes P1 (+ V) terminal to P15 (Addr0) terminal. The P1 (+ Vi) terminal and the P3 (-Vi) terminal are a pair of input terminals to which the input voltage Vi is externally input at both ends, and are connected to the input terminals of the first and second power conversion units 26 and 48. ing.

  The P2 (ON / OFF) terminal is an on / off terminal for switching between output and stop of the main output voltage Vo, and is connected to the first drive circuit 42. Here, when a low-level voltage is input from the outside (or grounded to the P3 (−Vi) terminal), the first drive circuit 42 stands by and the switching element 28 can be turned on / off. Further, when a high level voltage is input from the outside, the first drive circuit 42 becomes inoperable and the main output voltage Vo decreases. Note that a method other than limiting the operation of the first drive circuit 42 may be used as a method of making the switch-on element 28 in an on / off state.

  The P4 (+ Vo) terminal and the P8 (−Vo) terminal are a pair of main output terminals that output the main output voltage Vo from both ends, and are connected to the output terminal of the first rectifying and smoothing circuit 32.

  The P7 (+ S) terminal and the P5 (-S) terminal are a pair of sensing terminals for detecting the main output voltage Vo at a position close to the load, and are connected to the input terminal of the first voltage detection circuit 36. . For example, when the wiring from the switching power supply 10 to the load is long, the voltage drop of the wiring cannot be ignored, and is used to cancel this.

  The P6 (TRM) terminal is a trimming terminal for changing the target value of the main output voltage Vo, and is connected to the first voltage detection circuit 36. Here, the first voltage detection circuit 36 is configured as an analog error amplifier circuit (a circuit that amplifies and outputs the difference between the main output voltage Vo and the reference voltage), and a resistor or the like is connected to the P6 (TRM) terminal. The reference voltage is changed by external connection, and the target value of the main output voltage Vo is varied. When the target value is set by the first control unit 38, the P6 (TRM) terminal is connected to the first control unit 38.

  The P9 (Pw-Good) terminal is a power good terminal for externally outputting a signal indicating that the main output voltage Vo is being output, and is connected to the first control unit 38. The P9 (Pw-Good) terminal is an open drain output here, and is used by being pulled up to an external DC voltage. The main output voltage Vo detected by the first voltage detection circuit 36 is a predetermined value (main output voltage Vo). When the value is lower than the target value, the high level is output, and when the output is high, the low level is output.

  The P10 (S-Gnd) terminal is an external ground terminal connected to the ground of the external device, and is connected to the ground of the first control unit 38 and the ground of the second rectifying and smoothing circuit 54.

The P11 (Data) terminal and the P13 (Clock) terminal are serial communication terminals (I2C clock transmission / reception terminal and data transmission / reception terminal), and both are connected to the I2C module 38a. The P11 (Data) and P13 (Clock) terminals are open-drain outputs that are used by pulling up to an external DC voltage.
The P12 (SMBAlert) terminal is an alarm terminal for outputting an alarm signal (high level or low level) when any abnormality occurs in the first converter 20 or the second converter 48. The first control unit 28 It is connected to the.

  A P15 (Addr0) terminal is a main address setting terminal to which an external resistor is connected in order to give an address for serial communication to the first control circuit 34, and is connected to the Addr0 pin of the first control unit 38.

  The P14 (Addr1 / Vr) terminal is a function variable terminal whose function is set by the switching means 24. The switching means 24 is, for example, a manual switching element 24a. As shown in FIG. 3A, the switching means 24 connects the P14 (Addr1 / Vr) terminal to the Addr1 pin of the first control unit 38 or outputs the regulator 56. Connect to the end or set to either one. Therefore, the P14 (Addr1 / Vr) terminal cooperates with the P15 (Addr0) terminal to give the address of the first control circuit 34 when the switch element 24a is set like the former, and the auxiliary address setting terminal (P14 When the switch element 24a is set as in the latter, it becomes an auxiliary output terminal (P14 (Vr) terminal) that outputs the auxiliary output voltage Vr as an operating voltage of the external device. When the P14 (Addr1 / Vr) terminal is set to the P14 (Vr) terminal, when the first control unit 38 allocates an address from the voltage values of the Addr0 pin and the Addr1 pin, the voltage of the Addr1 pin is ignored, and the Addr0 Note that it is programmed to allocate addresses based solely on pin voltages.

  The switching means 24 may have a configuration other than the manual switch element 24a. For example, as shown in FIG. 3B, if the switching means 24 is composed of a wiring pattern 24b (1) and a connection switching resistance element 24b (2), the mounting position of the resistance element 24b (2) is changed. Thus, the setting can be switched. Further, as shown in FIG. 3C, the switching unit 24 may be configured by a semiconductor switch 24 c so that the setting is switched upon receiving a command from the first control unit 38.

  Next, an example of a power supply system (power supply system 72) configured using the switching power supply apparatus 10 will be described with reference to FIG. The power supply system 72 is a system in which the switching power supply apparatus 10 supplies operating voltages to the loads 74 (1) and 74 (2), and these operations are monitored and controlled by the external device 76. Since the loads 74 (1) and 74 (2) and the external device 76 communicate with the switching power supply device 10, an I 2 C module is provided therein. The P14 (Addr1 / Vr) terminal, which is a function variable terminal of the switching power supply device 10, is set to the P14 (Vr) terminal, which is an auxiliary output terminal.

  In the switching power supply device 10, the P2 (ON / OFF) terminal is grounded to the P3 (-Vi) terminal, and the switching element 28 of the first converter 20 is operable. Therefore, when the input voltage Vi is applied between the P1 (+ Vi) and P3 (-Vi) terminals, the main output voltage Vo is generated between the P8 (+ Vo) and P4 (-Vo) terminals. The P8 (+ Vo) and P4 (−Vo) terminals are connected to the S8 (+ Vo) and S4 (−Vo) terminals of the loads 74 (1) and 74 (2), respectively, and the main output voltage Vo is applied to the load 74. Output as operation voltage (1), 74 (2). The P7 (+ S) and P5 (-S) terminals are connected to positions close to the S8 (+ Vo) and S4 (-Vo) terminals of the loads 74 (1) and 74 (2) to detect the main output voltage Vo To do.

  The P14 (Vr) and P10 (S-Gnd) terminals are respectively connected to the T14 (Vr) and T10 (S-Gnd) terminals of the external device 76, and the auxiliary output voltage Vr is output as an operating voltage for the external device 76. To do. The P10 (S-Gnd) terminal is connected to the S10 (S-Gnd) terminals of the loads 74 (1) and 74 (2), respectively, and serves as a common ground for the respective devices.

  A variable resistor is connected between the P6 (TRM) terminal and the P10 (S-Gnd) terminal, and the target value of the main output voltage Vo can be finely adjusted with this variable resistor.

  The P9 (Pw-Good) terminal is connected to the S9 (Pw-Good) terminal of the loads 74 (1) and 74 (2) and the T9 (Pw-Good) terminal of the external device 76, respectively, and the main output voltage Vo is When it rises to a value close to the target value, a power good signal is output. When receiving the power good signal, the external device 76 and the loads 74 (1) and 74 (2) perform appropriate operations according to the program. The P9 (Pw-Good) terminal is pulled up to the P14 (Vr) terminal via a resistor.

  The P12 (SMBAlert) terminal is connected to the T12 (SMBAlert) terminal of the external device 76 and outputs an alarm signal. Loads 74 (1) and 74 (2) also have an S12 (SMBAlert) terminal similar to the P12 (SMBAlert) terminal, and are connected to the T12 (SMBAlert) terminal of the external device 76. Output a signal. When receiving the alarm signal, the external device 76 performs a predetermined measure according to the program.

  A predetermined resistor is connected between the P15 (Addr0) terminal and the P10 (S-Gnd) terminal, and an address for communication of the switching power supply device 10 is set. Here, since the P14 (Addr1 / Vr) terminal is set as the P14 (Vr) terminal, the address is set using only the voltage of the P15 (Addr0) terminal.

  The P11 (Data) and P13 (clock) terminals are connected to the T11 (Data) and T13 (clock) terminals of the external device 76, respectively, so that I2C communication is possible. The loads 74 (1) and 74 (2) also have similar S11 (Data) and S13 (clock) terminals, and are connected to the T11 (Data) and T13 (clock) terminals of the external device 76, respectively. Communication is possible. The P11 (Data) and P13 (clock) terminals are each pulled up to the P14 (Vr) terminal via a resistor.

  The information that the switching power supply device 10 transmits to the external device 76 includes, for example, data indicating the operating state of the switching power supply device 10 (input voltage Vi, main output voltage Vo, auxiliary output voltage Vr, switching frequency, specific circuit, etc. Element current, voltage, temperature). As a result, the external device 76 can accurately monitor the operating state of the switching power supply 10. Information transmitted from the external device 76 to the switching power supply 10 is a command to the first control unit 38. For example, the external device 76 transmits a command “send the detected value of the main output voltage Vo at intervals of 5 minutes”. Then, the first control unit 38 that has received this acquires information on the main output voltage Vo from the first voltage detection circuit 36 and transmits it to the external device 76 at intervals of 5 minutes. In addition, when the external device 76 transmits a command “make the main output voltage Vo down”, the first control unit 38 that has received the command stops the operation of the first drive circuit 42. The communication performed between the external device 76 and the load 74 (1) and the load 74 (2) is similar.

  The switching power supply 10 used for the power supply system 72 conforms to the PMbus standard, but the P14 (Addr1 / Vr) terminal is set to the P14 (Vr) terminal. Not compliant. However, there is an advantage that the configuration of the power supply system 72 can be made simpler than the power supply system 78 described later.

  Next, another example (power supply system 78) of a power supply system configured using the switching power supply device 10 will be described with reference to FIG. Here, the same components as those of the power supply system 72 are denoted by the same reference numerals and description thereof is omitted.

  The power supply system 78 differs greatly from the power supply system 72 in the specifications of the switching power supply 10 to be used, and the P14 (Addr1 / Vr) terminal, which is a function variable terminal, is set to the P14 (Addr1) terminal, which is an auxiliary address setting terminal. It is a point that conforms to the DOSA terminal layout standard. Therefore, an auxiliary power supply device 80 for supplying an operating voltage to the external device 76 is added.

  A predetermined resistor is connected between the P14 (Addr1) terminal and the P10 (S-Gnd) terminal, and the address for communication of the switching power supply 10 is set in cooperation with the P15 (Addr0) terminal. The auxiliary power supply device 80 is a device that converts the input voltage Vi into the auxiliary output voltage Vr and outputs the auxiliary output voltage Vr, and has an output terminal connected to the T14 (+ Vr) and T10 (S-Gnd) terminals of the external device 76. The auxiliary output voltage Vr is also used as a DC voltage for pulling up the P9 (Pw-Good) terminal, the P11 (Data) terminal, and the P13 (Clock) terminal. Other configurations and operations are the same as those of the power supply system 72.

  The power supply system 78 is more complicated in configuration than the power supply system 72 because the auxiliary power supply device 80 is added. However, since the industry standard product based on the PMbus standard and the DOSA terminal layout standard can be used as the switching power supply device 10, there is an advantage that the user can purchase a plurality of switching power supply devices. In addition, since a large number of addresses can be allocated, it is advantageous when the number of switching power supplies 10 and loads 74 is large. Even if the P9 (Pw-Good) terminal is changed to an on / off terminal (P9 (ON / OFF) terminal) for switching between output and stop of the main output voltage Vo, it must comply with the DOSA terminal layout standard. Can do.

  As described above, the switching power supply device 10 includes the I2C module 38a and the P11 (Data) and P13 (clock) terminals that are external connection terminals necessary for communication, so that the communication protocol conforms to the PMBus standard. be able to. Furthermore, by switching the setting of the switching means 24, specifications conforming to terminal arrangement standards such as DOSA (specifications suitable for the power supply system 78) and specifications that can simplify the power supply system (specifications suitable for the power supply system 72) Can be easily changed in the production process of the power supply device, and the specified product can be quickly produced and shipped regardless of which specification the user orders.

  In the switching power supply 10, the input and output of the first and second converters 20 and 22 are insulated, and the first control unit 38a including the I2C module 38a is provided in the output side circuit 46. Accordingly, the external device 76 and the loads 74 (1) and 74 (2) of the communication partner are connected to the output side circuit 46 (safe voltage side on the safety standard), so that no special insulation means is provided. However, the safety of the external device 76 and the like can be ensured. Further, the portion (first control unit 38a and the like) provided in the output side circuit 46 in the first control circuit 34 is configured to be operable by receiving the control voltage Vs of the second converter 22, After the input voltage Vi is input, the first control unit 38 and the like can be enabled before the first power conversion unit 26 starts operating. Therefore, since the first control unit 38 can control the operation of the first power conversion unit 26 from the beginning of switching, the rising characteristic of the main output voltage Vo can be variably adjusted easily and freely.

  The switching power supply device of the present invention is not limited to the above embodiment. The communication performed by the switching power supply device is not limited as long as it performs serial communication with an external device, and a serial communication terminal is also provided in accordance with the communication method. For example, when conforming to the PMbus standard or the SMBus standard (System Management Bus), it is preferable to provide the I2C module as described above and provide the P11 (Data) and P13 (Closk) terminals as serial communication terminals. In addition, when using the SPI method (Serial Peripheral Interface), the MicroWire method, or the like, a communication module for each method and a serial communication terminal corresponding thereto are provided.

  When the terminal arrangement is other than DOSA, the layout of the P1 (+ Vi) terminal to the P15 (Addr0) terminal may be changed. In addition, P2 (ON / OFF) terminal, P5 (+ S), P7 (-S) terminal, P6 (TRM) terminal, P9 (Pw-Good) terminal, P12 (SMBalert) are selectively omitted as necessary Thus, the function may be simplified, or the internal circuit may be made to be an input / output non-insulated type to reduce the cost and size of the apparatus.

  Further, the operation of switching the switching means to perform the initial setting of the variable function terminal may be performed at a factory that produces the switching power supply device, or may be performed when the user who purchased the switching power supply device incorporates the switching power supply device into the power supply system.

10 Switching power supply 18 External mounting terminals (P1 (+ Vi) terminal to P15 (Addr0) terminal)
20 first converter 22 second converter 24 switching means 26 first power converter 34 first control circuit 38a I2C module (serial communication module)
44, 68 Input side circuit 46, 70 Output side circuit 48 Second power converter 58 Second control circuit 76 External device
P1 (+ Vi) positive input terminal
P3 (-Vi) Negative input terminal
P4 (-Vo) Negative main output terminal
P8 (+ Vo) Positive main output terminal
P10 (S-Gnd) External ground terminal
P11 (Data), P13 (Clock) Serial communication terminal
P14 (Addr1 / Vr) Function variable terminal
P14 (Addr1) Auxiliary address setting pin
P14 (Vr) Auxiliary output terminal
P15 (Addr0) Main address setting pin
Vo Main output voltage
Vi input voltage
Vr Auxiliary output voltage
Vs Control voltage

Claims (4)

A first power converter that converts an input voltage into a main output voltage and outputs the first power converter; a first converter provided with a first control circuit that controls the operation of the first power converter; and the first control circuit A second communication circuit provided with a serial communication module, a second power converter that converts the input voltage into an auxiliary output voltage, and a second control circuit that controls the operation of the second power converter. And a plurality of external connection terminals connected to the other mounting board,
The plurality of external connection terminals include a pair of input terminals to which the input voltage is externally input at both ends,
A pair of main output terminals that output the main output voltage from both ends, and a serial communication terminal that is connected to an external device and enables communication between the serial communication module and the external device;
An external ground terminal that is connected to the ground of the external device, a main address setting terminal that is an external connection terminal for giving an address for serial communication to the first control circuit, and a function variable whose function setting can be switched. Terminal and
The function of the function variable terminal is set by built-in switching means, and the switching means provides the function variable terminal with the address of the first control circuit in cooperation with the main address setting terminal. A setting to be an auxiliary address setting terminal that is an external connection terminal and a setting to make the function variable terminal an auxiliary output terminal that outputs the auxiliary output voltage as an operation voltage of the external device are switchable. A switching power supply device comprising:   The switching power supply device according to claim 1, wherein the serial communication module is an I2C communication module, and a terminal for clock transmission / reception and a terminal for data transmission / reception are provided as the serial communication terminals.   Each internal circuit of the first and second converters is composed of an input side circuit and an output side circuit that are insulated from each other, the serial communication module, the pair of main output terminals, the serial communication terminals, and the external The switching power supply according to claim 1 or 2, wherein the ground terminal, the main address setting terminal, and the function variable terminal are provided in the output side circuit of the first or second converter.   The second power conversion unit converts the input voltage into the auxiliary output voltage and a control voltage for output, and the control voltage is provided in the output side circuit in the first control circuit. 4. The switching power supply device according to claim 3, wherein the switching power supply device is used as a voltage for operating a portion.

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