CN217037041U

CN217037041U - Direct current power port protection circuit and power supply device

Info

Publication number: CN217037041U
Application number: CN202220025522.7U
Authority: CN
Inventors: 徐朝阳; 梅纯; 武志超; 周小龙; 胡明杭
Original assignee: Wuhan Magmett Electric Co ltd
Current assignee: Wuhan Magmett Electric Co ltd
Priority date: 2022-01-06
Filing date: 2022-01-06
Publication date: 2022-07-22
Anticipated expiration: 2032-01-06

Abstract

The utility model relates to a direct current power port protection circuit and power supply equipment, the circuit comprises an anti-reverse switch unit, a switch protection unit and a drive unit, wherein when the polarity of an input power is connected reversely, the anti-reverse switch unit disconnects an input power loop to protect a power output port so as to protect a load and subsequent circuits thereof, the disconnection of the anti-reverse switch unit can cause a first end of the anti-reverse switch unit to generate a tip high-voltage signal, namely the cathode of the input power generates the tip high-voltage signal, so that the drive unit drives the switch protection unit to work to absorb the tip high-voltage signal and prevent the anti-reverse switch unit from overvoltage damage caused by the tip high-voltage signal so as to protect the anti-reverse switch unit, therefore, compared with the traditional direct current power port protection circuit, the direct current power port protection circuit increases the protection of the anti-reverse switch unit, namely the protection of the protection circuit, the protection effect of the circuit and the reliability of the system are further improved.

Description

Direct current power port protection circuit and power supply device

Technical Field

The utility model relates to the field of power supplies, in particular to a direct-current power port protection circuit and power supply equipment.

Background

In the application process, due to the influences of various reasons such as power supply voltage abnormity, electromagnetic environment complexity, illegal operation of constructors, thunder and lightning weather and the like, the situations of overvoltage, undervoltage, overcurrent, reverse polarity connection or signal interference and the like often occur in a direct current power port, and therefore the system power supply is damaged and influences are caused on subsequent circuits, the running reliability of the system is reduced, and therefore the direct current power port needs to be reliably protected. The current direct current power supply port protection circuit protects the direct current power supply port through some protection circuits, but lacks protection of the protection circuit, and reduces the protection effect and the system operation reliability of the protection circuit.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model aims to provide a direct-current power supply port protection circuit and power supply equipment, which can not only protect a direct-current power supply port, but also protect the protection circuit, and improve the protection effect of the circuit and the reliability of a system.

In order to solve the above technical problems, embodiments of the present invention provide the following technical solutions: in a first aspect, an embodiment of the present invention provides a dc power supply port protection circuit, where the dc power supply port protection circuit includes: the device comprises an anti-reverse switch unit, a switch protection unit and a driving unit;

the first end of the reverse switch unit is electrically connected with the negative electrode of the input power supply, and the second end of the reverse switch unit is electrically connected with the negative electrode of the power supply output port and used for protecting the power supply output port when the polarity of the input power supply is reversed;

the first end of the switch protection unit is electrically connected with the anode of the input power supply, the second end of the switch protection unit is respectively electrically connected with the cathode of the input power supply and the first end of the reverse-prevention switch unit, and the third end of the switch protection unit is electrically connected with the output end of the driving unit and used for protecting the reverse-prevention switch unit when the polarity of the input power supply is reversed; and the number of the first and second groups,

the first input end of the driving unit is electrically connected with the negative electrode of the input power supply, the second input end of the driving unit is electrically connected with the positive electrode of the input power supply, and the driving unit is used for driving the switch protection unit when the polarity of the input power supply is reversed so as to control the working state of the switch protection unit.

In some embodiments, the driving unit includes an optical coupling module, a first original edge of the optical coupling module is electrically connected to the negative terminal of the input power source, a second original edge of the optical coupling module is electrically connected to the positive terminal of the input power source, and an output end of the optical coupling module is electrically connected to the third terminal of the switch protection unit.

In some embodiments, the driving unit further includes a voltage stabilizing module, a negative electrode of the voltage stabilizing module is electrically connected to the second primary side end of the optical coupling module, and a positive electrode of the voltage stabilizing module is electrically connected to the positive electrode of the input power supply, and is configured to set a voltage threshold value at which the primary side circuit of the optical coupling module is turned on.

In some embodiments, the power supply further includes a slow-start switch unit, and the slow-start switch unit is electrically connected to the second end of the anti-reverse switch unit and the negative electrode of the power output port, respectively, and is configured to protect the power output port when the input power supply is turned on to provide power.

In some embodiments, the power supply further comprises a first-stage surge protection unit and a first-stage EMC filter unit, the first-stage surge protection unit is connected with the first-stage EMC filter unit in parallel, one end of the first-stage surge protection unit is electrically connected with the positive electrode of the input power supply, the other end of the first-stage surge protection unit is electrically connected with the negative electrode of the input power supply, the first end of the anti-reverse switching unit and the second end of the switch protection unit respectively, the first-stage surge protection unit is used for discharging differential mode surge energy between the positive electrode and the negative electrode of the power input port, and the first-stage EMC filter unit is used for suppressing differential mode surge energy between the positive electrode and the negative electrode of the power input port.

In some embodiments, the electronic device further includes a decoupling unit, one end of the decoupling unit is electrically connected to the negative electrode of the input power supply, the first stage surge protection unit, and the first stage EMC filter unit, and the other end of the decoupling unit is electrically connected to the first end of the anti-reverse switching unit and the second end of the switching protection unit, respectively, for suppressing surge energy.

In some embodiments, the protection device further comprises a second-stage surge protection unit and a second-stage EMC filter unit, the second-stage surge protection unit is connected with the second-stage EMC filter unit in parallel, one end of the second-stage surge protection unit is electrically connected with the positive electrode of the input power supply, the other end of the second-stage surge protection unit is electrically connected with the decoupling unit, the first end of the reverse-switch prevention unit and the second end of the switch protection unit respectively, and is used for discharging common-mode surge energy of the positive electrode and the negative electrode of the power input port to the ground, and the second-stage EMC filter unit is used for suppressing the common-mode surge energy of the positive electrode and the negative electrode of the power input port to the ground.

In some embodiments, a third stage surge protection unit and a third stage EMC filtering unit are also included, one end of the third-stage surge protection unit is electrically connected with the positive electrode of the input power supply, the other end of the third-stage surge protection unit is respectively electrically connected with the decoupling unit, the second-stage surge protection unit, the second-stage EMC filtering unit, the first end of the anti-reverse switch unit and the second end of the switch protection unit, the third-stage surge protection unit is used for absorbing residual surge energy of the power supply input port, one end of the third-stage EMC filtering unit is electrically connected with the positive electrode of the input power supply, the other end of the third-stage EMC filtering unit is respectively electrically connected with the second end of the anti-reverse switch unit, and the third-stage EMC filtering unit is used for suppressing residual surge energy of the power input port.

In some embodiments, the switch protection unit includes a first thyristor, a first gate resistor, and a second gate resistor, a cathode of the first thyristor is electrically connected to a positive terminal of the input power source, an anode of the first thyristor is electrically connected to a negative terminal of the input power source and the first end of the anti-reverse switch unit, a control terminal of the first thyristor is connected to one end of the first gate resistor and one end of the second gate resistor, another end of the first gate resistor is electrically connected to the positive terminal of the input power source, and another end of the second gate resistor is electrically connected to the output terminal of the driving unit.

In some embodiments, the anti-reverse switch unit includes a first MOS transistor, a first voltage regulator transistor, and a second voltage regulator transistor, a gate of the first MOS transistor is connected to a cathode of the second voltage regulator transistor and is configured to access a driving signal of the first MOS transistor, a drain of the first MOS transistor is electrically connected to a cathode of the first voltage regulator transistor, a negative electrode of the input power supply, and a second end of the switch protection unit, respectively, and a source of the first MOS transistor is electrically connected to an anode of the first voltage regulator transistor, an anode of the second voltage regulator transistor, and a negative electrode of the power output port, respectively.

In some embodiments, the optocoupler module includes a first optocoupler, the voltage regulator module includes a third voltage regulator tube, an anode of a primary light emitting diode of the first optocoupler is electrically connected with a negative electrode of the input power supply, a cathode of the primary light emitting diode of the first optocoupler is connected with a cathode of the third voltage regulator tube, an output end of the first optocoupler is electrically connected with a third end of the switch protection unit, and an anode of the third voltage regulator tube is electrically connected with a positive electrode of the input power supply.

In some embodiments, the soft-start switch unit includes a second MOS transistor, a fourth voltage-regulator transistor, a fifth voltage-regulator transistor, and a first variable resistor, a gate of the second MOS transistor is connected to a cathode of the fifth voltage-regulator transistor and is configured to access a driving signal of the second MOS transistor, a drain of the second MOS transistor is electrically connected to a cathode of the fourth voltage-regulator transistor, one end of the first variable resistor, and a cathode of the power output port, respectively, and a source of the second MOS transistor is electrically connected to an anode of the fourth voltage-regulator transistor, an anode of the fifth voltage-regulator transistor, the other end of the first variable resistor, and a second end of the anti-reverse switch unit, respectively.

In a second aspect, an embodiment of the present invention provides a power supply apparatus including: the direct current power supply port protection circuit is described above.

In each embodiment of the utility model, the direct current power port protection circuit comprises an anti-reverse switch unit, a switch protection unit and a driving unit, wherein when the polarity of an input power is connected reversely, the anti-reverse switch unit disconnects an input power loop to protect a power output port so as to protect a load and a subsequent circuit thereof, disconnection of the anti-reverse switch unit can cause a first end of the anti-reverse switch unit to generate a tip high-voltage signal, namely the input power cathode generates the tip high-voltage signal, so that the driving unit drives the switch protection unit to work to absorb the tip high-voltage signal and prevent the anti-reverse switch unit from overvoltage damage caused by the tip high-voltage signal so as to protect the anti-reverse switch unit, therefore, compared with the traditional direct current power port protection circuit, the direct current power port protection circuit increases protection of the anti-reverse switch unit, namely the protection of the protection circuit itself, the protection effect of the circuit and the reliability of the system are further improved.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings which correspond to and are not to be construed as limiting the embodiments, in which elements having the same reference numeral designations represent like elements throughout, and in which the drawings are not to be construed as limiting in scale unless otherwise specified.

Fig. 1 is a schematic structural diagram of one of power supply devices according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a dc power port protection circuit according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a dc power port protection circuit according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a dc power port protection circuit according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a power supply device according to an embodiment of the present invention. As shown in fig. 1, the power supply apparatus includes a dc power port protection circuit 100, a power supply 200, and a load 300.

The power supply 200 is connected to the dc power port protection circuit 100, the power supply 200 supplies power to the load 300 through the power output port, and the dc power port protection circuit 100 protects the power port, the subsequent circuits, and the load 300. The power supply 200 may be a dc power supply or an ac power supply, and when the power supply 200 is an ac power supply, the dc power supply is provided to the load 300 through the dc power port protection circuit 100 after being rectified and filtered, and the power supply 200 may be a power supply circuit composed of any suitable discrete components, for example, in some embodiments, the power supply 200 is a power supply circuit composed of a filter circuit, a rectifier circuit, and a voltage regulator circuit, and further for example, in some embodiments, the power supply 200 is an integrated power supply chip.

The dc power port protection circuit 100 protects the subsequent circuits of the power port and the load 300, for example, protects the load by EMC protection, lightning surge protection, reverse connection protection of the input power, and fault isolation protection, so as to avoid the power damage of the system to which the power port belongs and the influence on the subsequent circuits and the load 300. However, the conventional dc power port protection circuit 100 lacks protection of the protection circuit itself, and if the protection circuit itself is damaged by a high-voltage signal during operation, for example, the protection circuit itself is cut off input surge, and when protecting a subsequent circuit, the protection circuit is affected by a tip high-voltage signal and loses the protection function, the protection effect of the protection circuit and the reliability of the system are reduced.

Referring to fig. 2, fig. 2 is a diagram of a dc power port protection circuit 100 according to an embodiment of the present invention, as shown in fig. 2, the dc power port protection circuit 100 includes an anti-reverse switch unit 101, a switch protection unit 102, and a driving unit 103, wherein a first end of the anti-reverse switch unit 101 is electrically connected to a negative Vin-of an input power, and a second end of the anti-reverse switch unit 101 is electrically connected to a negative Vbus-of a power output port. The reverse prevention switch unit 101 is connected in series to the negative line of the input power supply, and when the polarity of the input power supply is reversed, the reverse prevention switch unit 101 acts to cut off the loop of the input power supply, and further cut off the power supply loop of the subsequent circuit and the load 300, so as to protect the power output port, the subsequent circuit and the load 300.

When the polarity of the input power is reversed, the reverse-prevention switch unit 101 is in a disconnected state, and the input power loop is cut off. However, due to the disconnection of the anti-reverse switch unit 101, a tip high voltage signal is generated at the first end of the anti-reverse switch unit, that is, the negative electrode Vin-of the input power source is the tip high voltage signal, and the tip high voltage signal may cause damage to the anti-reverse switch unit 101.

A first end of the switch protection unit 102 is electrically connected to the positive electrode Vin + of the input power supply, a second end of the switch protection unit 102 is electrically connected to the negative electrode Vin-of the input power supply and the first end of the anti-reverse switch unit 101, respectively, and a third end of the switch protection unit 102 is electrically connected to the output end of the driving unit 103. The first input end of the driving unit 103 is electrically connected to the negative electrode Vin-of the input power source, and the second input end of the driving unit 103 is electrically connected to the positive electrode Vin + of the input power source.

When the polarity of the input power is reversed, the first input end of the driving unit 103 is connected with a tip high-voltage signal, the second input end of the driving unit 103 is connected with the anode of the input power, the voltage value of the tip high-voltage signal is far greater than the voltage of the anode of the input power, the driving unit 103 is automatically triggered to output the driving signal through the output end of the driving unit 103 so as to drive the switch protection unit 102 to work, so that the working state of the switch protection unit 102 is controlled, the switch protection unit 102 absorbs the tip high-voltage signal, and the tip high-voltage signal is prevented from damaging the reverse-prevention switch unit 101 and is protected.

Therefore, when the polarity of the input power is reversed, the direct current power port protection circuit can protect a load and a subsequent circuit thereof, and meanwhile, the driving unit drives the switch protection unit to work, so that the phenomenon that the reverse switch prevention unit is damaged by overvoltage due to a tip high-voltage signal is prevented, and the switch protection unit is protected.

Referring to fig. 3, fig. 3 is a schematic circuit structure diagram of a dc power port protection circuit according to an embodiment of the present invention, as shown in fig. 3, the driving unit 103 includes an optical coupling module 1031, a first primary end of the optical coupling module 1031 is electrically connected to a negative terminal Vin-of the input power, a second primary end of the optical coupling module 1031 is electrically connected to a positive terminal Vin + of the input power, and an output end of the optical coupling module 1031 is electrically connected to a third terminal of the switch protection unit 102.

The optocoupler module 1031 may isolate the input end signal from the output end signal, that is, isolate the input power end signal from the output driving signal. When the polarity of the input power is reversed, the negative electrode Vin-of the input power is a tip high-voltage signal, the first primary side input end of the optical coupling module 1031 is connected with the tip high-voltage signal, the second primary side input end of the optical coupling module 1031 is connected with the positive electrode signal of the input power, the voltage of the tip high-voltage signal is far greater than the positive electrode voltage of the input power, a primary side circuit of the optical coupling module 1031 is conducted, and then the output end of the optical coupling module 1031 outputs a high-level signal, and the high-level signal is used for driving the switch protection unit 102 to act.

In some embodiments, the driving unit 103 further includes a voltage stabilizing module 1032, a negative electrode of the voltage stabilizing module 1032 is electrically connected to the second primary side end of the optical coupling module 1031, and a positive electrode of the voltage stabilizing module 1032 is electrically connected to the positive electrode Vin + of the input power source, and is configured to protect the primary side of the optical coupling module 1031.

The voltage stabilizing module 1032 sets a voltage threshold for switching on the primary side circuit of the optocoupler module 1031, and only when the difference between the voltage of the tip high-voltage signal and the positive voltage of the input power supply is greater than the voltage stabilizing value of the voltage stabilizing module 1032, the primary side circuit of the optocoupler module 1031 is switched on, so that the primary side circuit of the optocoupler module 1031 is prevented from being switched on at will, that is, the driving unit 103 is prevented from outputting the driving signal at will, and the switch protection unit 102 is driven to act.

In some embodiments, the driving unit 103 further includes a controller, which can perform data processing and logic operations, and output driving signals of the anti-reverse switching unit 101 and other switching units.

The controller may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a single chip, an arm (acorn RISC machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. Also, the controller may be any conventional processor, controller, microcontroller, or state machine. A controller may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP, and/or any other such configuration. The specific model and composition of the controller can be set as desired.

In some embodiments, referring to fig. 3, the dc power port protection circuit 100 further includes a slow-start switch unit 104, and the slow-start switch unit 104 is electrically connected to the second terminal of the reverse-protection switch unit 101 and the negative electrode Vbus-of the power output port, respectively.

When the input power supply is turned on to provide power, the slow-start switch unit 104 first supplies power to the subsequent circuit or the load 300 through the power output port, and then the slow-start switch unit 104 acts to enable the input power supply to form a loop and supply power to the subsequent circuit or the load 300, so that the power output port is protected, the input power supply is prevented from being impacted, and power-on buffering is achieved. In some embodiments, the soft-start switch unit 104 is turned on or off according to the input voltage and the output voltage of the input power source, that is, the soft-start switch unit 104 is turned on when the output voltage is close to the input voltage and within the rated operating range, and the soft-start switch unit 104 is turned off if the voltage difference across the soft-start switch unit is greater than 10V or the input voltage is over-voltage.

In some embodiments, the dc power port protection circuit 100 further includes a first surge protection unit 105 and a first EMC filter unit 106, the first surge protection unit 105 is connected in parallel with the first EMC filter unit 106, one end of the first surge protection unit 105 is electrically connected to the positive terminal Vin + of the input power source, the other end of the first surge protection unit 105 is respectively electrically connected to the negative terminal Vin of the input power source, the first end of the anti-reverse switch unit 101 and the second end of the switch protection unit 102.

When a lightning surge signal appears at an input power end, the first-stage surge protection unit 105 discharges differential mode surge energy between the positive electrode and the negative electrode of the power source input port, surge protection is performed on a subsequent circuit and a load 300 at the power source output port, the first-stage EMC filtering unit 106 inhibits the differential mode surge energy between the positive electrode and the negative electrode of the power source input port, and the subsequent circuit and the load 300 at the power source output port are further subjected to surge protection.

In some embodiments, the dc power port protection circuit 100 further includes a decoupling unit 107, one end of the decoupling unit 107 is electrically connected to the negative Vin "of the input power, the first surge protection unit 105 and the first EMC filter unit 106, and the other end of the decoupling unit 107 is electrically connected to the first end of the anti-reverse switch unit 101 and the second end of the switch protection unit 102.

The decoupling unit 107 is connected in series to the negative line of the power supply and is disposed behind the first-stage surge protection unit 105 and the first-stage EMC filter unit 106, and the decoupling unit 107 includes devices such as inductors, and the current of the inductors does not increase rapidly.

In some embodiments, the dc power port protection circuit 100 further includes a second-stage surge protection unit 108 and a second-stage EMC filtering unit 109, the second-stage surge protection unit 108 is connected in parallel with the second-stage EMC filtering unit 109, one end of the second-stage surge protection unit 108 is electrically connected to the positive electrode Vin + of the input power source, and the other end of the second-stage surge protection unit 108 is electrically connected to the decoupling unit 107, the first end of the anti-reverse switch unit 101, and the second end of the switch protection unit 102.

After the second-stage surge protection unit 108 and the second-stage EMC filter unit 109 are disposed behind the decoupling unit 107, when a surge signal occurs at an input power end, the second-stage surge protection unit 108 discharges common-mode surge energy of the positive and negative poles of the power input port to the ground, so as to perform surge protection on a subsequent circuit and a load 300 at the power output port, and the second-stage EMC filter unit 109 suppresses the common-mode surge energy of the positive and negative poles of the power input port to the ground, so as to further perform surge protection on the subsequent circuit and the load 300 at the power output port.

In some embodiments, the dc power port protection circuit 100 further includes a third-stage surge protection unit 110 and a third-stage EMC filtering unit 111, one end of the third-stage surge protection unit 110 is electrically connected to the positive terminal Vin + of the input power source, the other end of the third-stage surge protection unit 110 is electrically connected to the decoupling unit 107, the second-stage surge protection unit 108, the second-stage EMC filtering unit 109, the first end of the anti-reverse switching unit 101 and the second end of the switching protection unit 102, one end of the third-stage EMC filtering unit 111 is electrically connected to the positive terminal Vin + of the input power source, and the other end of the third-stage EMC filtering unit 111 is electrically connected to the second end of the anti-reverse switching unit 101.

The third-stage surge protection unit 110 is disposed before the anti-reverse switching unit 101 and the switch protection unit 102, and the third-stage EMC filtering unit 111 is disposed after the anti-reverse switching unit 101 and the switch protection unit 102. When a surge signal appears at an input power supply end, the third-stage surge protection unit 110 absorbs the residual surge energy at the power supply input port to perform surge protection on a subsequent circuit and a load 300 at the power supply output port, and the third-stage EMC filtering unit 111 is used for suppressing the residual surge energy at the power supply input port and further performing surge protection on the subsequent circuit and the load 300 at the power supply output port.

The multi-stage surge protection unit can effectively absorb lightning surge energy to protect a rear-stage circuit, and the multi-stage EMC filtering unit has excellent EMC characteristics.

In some embodiments, the dc power port protection circuit 100 further includes a plurality of input fuse units 112, which are respectively connected in series to the positive line of the input power and the negative line of the input power.

In some embodiments, the dc power supply port protection circuit 100 further includes a signal collection unit 113, where the signal collection unit 113 may collect a voltage signal and a current signal at an input end, and also collect a voltage signal and a current signal at an output end, and may transmit the collected voltage signal or current signal to a controller in the driving unit 103, where the controller performs corresponding processing on the voltage signal or current signal, and outputs a corresponding driving signal.

Referring to fig. 4, fig. 4 is a schematic circuit diagram of a dc power port protection circuit according to an embodiment of the present invention, as shown in fig. 4, the switch protection unit 102 includes a first thyristor SCR1, a first gate resistor R1, and a second gate resistor R2, the cathode of the first thyristor SCR1 is electrically connected to the anode of the input power source Vin +, the anode of the first thyristor SCR1 is electrically connected with the negative electrode Vin-of the input power supply and the first end of the anti-reverse switch unit 101 respectively, the control electrode of the first thyristor SCR1 is respectively connected to one end of the first gate resistor R1 and one end of the second gate resistor R2, the other end of the first gate resistor R1 is electrically connected to the positive electrode Vin + of the input power supply, the other end of the second gate resistor R2 is electrically connected to the output end of the driving unit 103.

The anti-reverse switch unit 101 comprises a first MOS transistor Q1, a first voltage regulator D1 and a second voltage regulator D2, wherein a gate of the first MOS transistor Q1 is connected with a cathode of the second voltage regulator D2 and is used for accessing a driving signal of the first MOS transistor Q1, a drain of the first MOS transistor Q1 is electrically connected with a cathode of the first voltage regulator D1, a negative electrode Vin of the input power supply and a second end of the switch protection unit 102, specifically, a drain of the first MOS transistor Q1 is electrically connected with an anode of a first thyristor SCR1, and a source of the first MOS transistor Q1 is electrically connected with an anode of the first voltage regulator D1, an anode of the second voltage regulator D2 and a negative electrode Vbus of the power output port.

The anti-reverse switch unit 101 further comprises a first resistor R3 and a second resistor R4, wherein one end of the first resistor R3 is used for accessing a driving signal of the first MOS transistor Q1, the other end of the first resistor R3 is respectively connected with one end of the second resistor R4, the gate of the first MOS transistor Q1 and the cathode of the second regulator D2, and the other end of the second resistor R4 is respectively connected with the source of the first MOS transistor Q1 and the anode of the second regulator D2. The first MOS tube Q1 selects a MOSFET with smaller on-resistance, so that the on-loss can be reduced, the first voltage-regulator tube D1 plays a role in voltage clamp protection at the moment of turning off the first MOS tube Q1, and the first voltage-regulator tube D1 is connected in parallel to the grid drive of the first MOS tube Q1, so that the grid is protected in a clamp manner.

The optical coupler module 1031 includes a first optical coupler U1, the voltage stabilizing module 1032 includes a third voltage regulator tube D3, an anode of a primary side light emitting diode of the first optical coupler U1 is electrically connected with a negative electrode Vin-of the input power supply, a cathode of a primary side light emitting diode of the first optical coupler U1 is connected with a cathode of the third voltage regulator tube D3, an output end of the first optical coupler U1 is connected with a second gate resistor R2, and an anode of the third voltage regulator tube D3 is electrically connected with a positive electrode Vin + of the input power supply. The anode of the primary side light emitting diode of the first optocoupler U1 is a pin 1, the cathode of the primary side light emitting diode of the first optocoupler U1 is a pin 3, the output end of the first optocoupler U1 is a pin 5, the pin 4 of the first optocoupler U1 is grounded, and the pin 6 of the first optocoupler U1 is connected with a power supply VCC.

The driving unit 103 further comprises a third resistor R5 and a first diode D4, the third resistor R5 is connected in series between the negative electrode Vin-of the input power source and the anode of the primary side light emitting diode of the first optocoupler U1, the cathode of the first diode D4 is connected with the anode of the primary side light emitting diode of the first optocoupler U1, and the anode of the first diode D4 is connected with the cathode of the primary side light emitting diode of the first optocoupler U1. The third resistor R5 is a current-limiting resistor, the first diode D4 protects the primary led of the first optocoupler, and when the input power voltage is high, the first diode D4 clamps the voltage at the two ends of the primary led of the first optocoupler U1 to the diode on-voltage, so as to prevent the primary led from being damaged by high voltage.

The slow-start switch unit 104 comprises a second MOS transistor Q2, a fourth regulator tube D5, a fifth regulator tube D6 and a first variable resistor RT1, the gate of the second MOS transistor Q2 is connected with the cathode of the fifth regulator tube D6, and is used for accessing a driving signal of the second MOS transistor Q2, a drain of the second MOS transistor Q2 is electrically connected with a cathode of the fourth regulator diode D5, one end of the first variable resistor RT1 and a cathode Vbus of the power output port respectively, a source of the second MOS transistor Q2 is electrically connected to the anode of the fourth regulator D5, the anode of the fifth regulator D6, the other end of the first variable resistor RT1, and the second end of the anti-reverse switch unit 101, respectively, and specifically, a source of the second MOS transistor Q2 is electrically connected to the anode of the fourth regulator D5, the anode of the fifth regulator D6, the other end of the first variable resistor RT1, and the source of the first MOS transistor Q1, respectively. The second MOS transistor Q2 is an MOSFET with smaller on-resistance, so that the on-loss can be reduced, and the fourth voltage-regulator tube D5 plays a role in voltage clamping protection at the moment when the second MOS transistor Q2 is turned off; the fifth voltage-regulator tube D6 is connected in parallel to the gate drive of the second MOS tube Q2, and plays a role in clamping protection for the gate.

In the embodiment of the present invention, the first MOS transistor Q1 and the second MOS transistor Q2 are both NMOS transistors, and the driving signals of the first MOS transistor Q1 and the second MOS transistor Q2 may be generated by separate driving circuits, or may be output by a controller, which is not limited herein.

The slow-start switch unit 104 further includes a fourth resistor R6 and a fifth resistor R7, wherein one end of the fourth resistor R6 is used for accessing a driving signal of the second MOS transistor Q2, the other end of the fourth resistor R6 is respectively connected to one end of the fifth resistor R7, the gate of the second MOS transistor Q2 and the cathode of the fifth regulator D6, and the other end of the fifth resistor R7 is respectively connected to the source of the second MOS transistor Q2 and the anode of the fifth regulator D6.

Before the first stage of surge protection unit 105, the dc power port protection circuit 100 further includes an input fuse unit 112, and the input fuse unit 112 includes a fuse F1 connected in series with the positive pole of the input power source and a fuse F2 connected in series with the negative pole of the input power source.

The first-stage surge protection unit 105 comprises a plurality of ceramic gas discharge tubes DG1 connected in parallel between the positive electrode and the negative electrode of the input power supply, and a first ceramic chip capacitor C1, a second ceramic chip capacitor C2, a third ceramic chip capacitor C3 and a fourth ceramic chip capacitor C4 which are respectively connected between the middle sections of the ceramic gas discharge tubes DG1 and the negative electrode of the input power supply line in a bridging manner. The mode of adopting the multi-section gas discharge tube can improve the arc voltage, thereby improving the follow current interruption capability; in addition, each section of the multiple sections of gas discharge tubes can be broken down step by adding a capacitor network, so that the overall breakdown voltage can be reduced and the overall breakdown voltage reaction time can be prolonged, and the first-stage surge protection unit 105 is mainly used for discharging differential mode surge energy between the anode and the cathode of the input port.

The first-stage EMC filtering unit 106 includes a first differential-mode filtering capacitor CX1 connected in parallel between the positive electrode and the negative electrode of the input power source, a first common-mode filtering capacitor CY1 connected in parallel between the positive electrode of the input power source and the ground, and a second common-mode filtering capacitor CY2 connected in parallel between the negative electrode of the input power source and the ground, and further includes a sixth resistor R8 and a seventh resistor R9, wherein the sixth resistor R8 and the seventh resistor R9 are connected in series and then connected in parallel at two ends of the differential-mode filtering capacitor CX1 to serve as the discharging dummy load 300.

The decoupling unit 107 comprises an air-core inductor L1, the air-core inductor is connected in series with the negative pole line of the input power supply and is placed behind the first-stage surge protection unit 105 and the first-stage EMC filtering unit 106, the anti-saturation capacity of the air-core inductor L1 is strong, when a surge occurs, the surge is cut off or blocked, the impact of the surge on a subsequent circuit is prevented, and the effect of restraining the current change is achieved.

The second-stage surge protection unit 108 comprises a gas discharge tube DG2 connected in parallel between the positive pole of the input power supply and the ground, and a piezoresistor RV1 connected between the negative pole of the input power supply and the ground, and the second-stage surge protection unit 108 is mainly used for discharging and consuming common-mode surge energy between the positive pole and the negative pole of the input power supply and the ground.

The second-stage EMC filter unit 109 includes a second differential-mode filter capacitor CX2, a first common-mode inductor L2, a third common-mode filter capacitor CY3 from the positive electrode to the ground, a fourth common-mode filter capacitor CY4 from the negative electrode to the ground, a third differential-mode filter capacitor CX3 and a second common-mode inductor L3, the second differential-mode filter capacitor CX2 is connected in parallel between pin 1 and pin 2 of the first common-mode inductor L2, the third common-mode filter capacitor CY3 and the fourth common-mode filter capacitor CY4 are connected in series and then connected in parallel between pin 3 and pin 4 of the first common-mode inductor L2, meanwhile, the third common-mode filter capacitor CY3 and the fourth common-mode filter capacitor CY4 are connected between a pin 1 and a pin 4 of the second common-mode inductor L3 in parallel, the third common-mode filter capacitor CY3 and the fourth common-mode filter capacitor CY4 are arranged between the first common-mode inductor L2 and the second common-mode inductor L3, a pin 2 of the third common-mode filter capacitor CY3 is connected with the anode Vin + of the input power supply, and a pin 3 of the third common-mode filter capacitor CY3 is connected with the cathode Vin-.

The third-stage surge protection unit 110 comprises a bidirectional TVS tube D7 connected in parallel between a positive electrode and a negative electrode; and clamping and absorbing the residual surge voltage through the TVS tube.

The third-stage EMC filtering unit 111 includes a fifth common-mode filtering capacitor CY5 between the positive electrode and the ground, a sixth common-mode filtering capacitor CY6 between the negative electrode and the ground, a capacitor EC1 for differential-mode filtering and energy storage, and a first dummy load resistor R10 and a second dummy load resistor R11 which are connected in series and then connected in parallel with the capacitor EC 1.

In some embodiments, the dc power source port protection circuit 100 further includes a signal collection unit, which can collect voltage and current signals at a power input end, and can also collect voltage and current signals at a power output end, and then transmit the collected signals to the driving unit 103, and the driving unit 103 performs logic processing according to electrical signals at the input end and the output end and outputs driving signals to control on and off of the anti-reverse switch unit 101, the switch protection unit 102, and the slow-start switch unit 104.

In conjunction with fig. 4, the operation principle of the dc power port protection circuit 100 can be described as follows:

when lightning surge occurs, a multi-stage surge protection circuit is adopted, and the first-stage surge protection unit 105, the second-stage surge protection unit 108 and the third-stage surge protection unit 110 can effectively absorb lightning surge energy and protect a rear-stage circuit. In addition, the dc power port protection circuit 100 employs a multi-stage differential mode common mode filter circuit, and has excellent EMC characteristics. The slow-start switch unit 104 can also implement power-on buffering to prevent the impact of the sudden access of the input power source on the subsequent circuits.

When the polarity of the input power is reversed, the first MOS transistor Q1 is driven to turn off, so as to cut off the input power loop and protect the subsequent circuits, the output power port and the load 300. Meanwhile, because the first MOS transistor Q1 is turned off, a tip high-voltage signal is generated at the drain of the first MOS transistor Q1, that is, the negative voltage of the input power supply is the tip high-voltage signal voltage, which is much greater than the positive voltage of the input power supply, so that the primary side light emitting diode of the optocoupler U1 is turned on, so that the optocoupler U1 outputs a high-level signal through its 5 pins, the high-level signal acts on the control electrode of the first thyristor SCR1 to control the turn-on of the first thyristor SCR1, and the tip high-voltage signal at the drain of the first MOS transistor Q1 is absorbed, thereby reliably protecting the first MOS transistor Q1, avoiding overvoltage damage when the circuit is cut off, and further improving the protection effect of the circuit and the reliability of the system.

In summary, when the polarity of the input power is reversed, the dc power port protection circuit can protect the load and the subsequent circuits thereof, and the driving unit drives the switch protection unit to work to prevent the reverse switch unit from overvoltage damage due to the tip high-voltage signal, so as to protect the switch protection unit.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; within the idea of the utility model, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the utility model as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A DC power port protection circuit, comprising: the device comprises an anti-reverse switch unit, a switch protection unit and a driving unit;

the first end of the switch protection unit is electrically connected with the anode of the input power supply, the second end of the switch protection unit is respectively electrically connected with the cathode of the input power supply and the first end of the reverse-prevention switch unit, and the third end of the switch protection unit is electrically connected with the output end of the driving unit and used for protecting the reverse-prevention switch unit when the polarity of the input power supply is reversed; and (c) a second step of,

2. The protection circuit as claimed in claim 1, wherein the driving unit includes an optocoupler module, a first original side of the optocoupler module is electrically connected to the negative electrode of the input power, a second original side of the optocoupler module is electrically connected to the positive electrode of the input power, and an output end of the optocoupler module is electrically connected to the third end of the switch protection unit.

3. The protection circuit for DC power port as claimed in claim 2, wherein the driving unit further comprises a voltage stabilizing module, a negative electrode of the voltage stabilizing module is electrically connected to the second primary side of the optical coupling module, and a positive electrode of the voltage stabilizing module is electrically connected to the positive electrode of the input power source for setting a voltage threshold value for the primary side circuit of the optical coupling module to be turned on.

4. The protection circuit for DC power port as claimed in claim 1, further comprising a slow-start switch unit electrically connected to the second terminal of the anti-reverse switch unit and the negative terminal of the power output port, respectively, for protecting the power output port when the input power is turned on to provide power.

5. The protection circuit of claim 1, further comprising a first surge protection unit and a first EMC filter unit, wherein the first surge protection unit is connected in parallel with the first EMC filter unit, and one end of the first surge protection unit is electrically connected to the positive electrode of the input power source, and the other end of the first surge protection unit is electrically connected to the negative electrode of the input power source, the first end of the anti-reverse switch unit and the second end of the switch protection unit respectively for discharging differential mode surge energy between the positive electrode and the negative electrode of the power source input port, and the first EMC filter unit is used for suppressing differential mode surge energy between the positive electrode and the negative electrode of the power source input port.

6. The protection circuit for DC power port as claimed in claim 5, further comprising a decoupling unit, wherein one end of the decoupling unit is electrically connected to the negative electrode of the input power supply, the first stage surge protection unit and the first stage EMC filtering unit, and the other end of the decoupling unit is electrically connected to the first end of the anti-reverse switching unit and the second end of the switch protection unit, respectively, for suppressing surge energy.

7. The protection circuit for the direct current power port as claimed in claim 6, further comprising a second-stage surge protection unit and a second-stage EMC filtering unit, wherein the second-stage surge protection unit is connected in parallel with the second-stage EMC filtering unit, one end of the second-stage surge protection unit is electrically connected to the positive electrode of the input power source, the other end of the second-stage surge protection unit is electrically connected to the decoupling unit, the first end of the anti-reverse switching unit and the second end of the switch protection unit respectively, and is used for discharging the common-mode surge energy of the positive electrode and the negative electrode of the power input port to the ground, and the second-stage EMC filtering unit is used for suppressing the common-mode surge energy of the positive electrode and the negative electrode of the power input port to the ground.

8. The DC power port protection circuit of claim 7, further comprising a third stage surge protection unit and a third stage EMC filter unit, one end of the third-stage surge protection unit is electrically connected with the positive electrode of the input power supply, the other end of the third-stage surge protection unit is respectively electrically connected with the decoupling unit, the second-stage surge protection unit, the second-stage EMC filtering unit, the first end of the anti-reverse switch unit and the second end of the switch protection unit, the third stage surge protection unit is used for absorbing residual surge energy of the power input port, one end of the third-stage EMC filtering unit is electrically connected with the positive electrode of the input power supply, the other end of the third-stage EMC filtering unit is respectively electrically connected with the second end of the anti-reverse switch unit, the third-stage EMC filtering unit is used for suppressing residual surge energy of the power supply input port.

9. The protection circuit as claimed in any one of claims 1 to 8, wherein the switch protection unit comprises a first thyristor, a first gate resistor and a second gate resistor, a cathode of the first thyristor is electrically connected to an anode of the input power source, an anode of the first thyristor is electrically connected to a cathode of the input power source and a first end of the anti-reverse switch unit, a control electrode of the first thyristor is electrically connected to one end of the first gate resistor and one end of the second gate resistor, the other end of the first gate resistor is electrically connected to the anode of the input power source, and the other end of the second gate resistor is electrically connected to the output end of the driving unit.

10. The direct current power port protection circuit as claimed in any one of claims 1 to 8, wherein the reverse-blocking switch unit includes a first MOS transistor, a first voltage regulator transistor and a second voltage regulator transistor, a gate of the first MOS transistor is connected to a cathode of the second voltage regulator transistor and is used for accessing a driving signal of the first MOS transistor, a drain of the first MOS transistor is electrically connected to a cathode of the first voltage regulator transistor, a negative electrode of the input power source and a second end of the switch protection unit, respectively, and a source of the first MOS transistor is electrically connected to an anode of the first voltage regulator transistor, an anode of the second voltage regulator transistor and a negative electrode of the power output port, respectively.

11. The protection circuit for DC power port as claimed in any one of claims 3 to 8, wherein the optocoupler module comprises a first optocoupler, the voltage regulator module comprises a third voltage regulator tube, an anode of a primary LED of the first optocoupler is electrically connected to a negative electrode of the input power supply, a cathode of the primary LED of the first optocoupler is connected to a cathode of the third voltage regulator tube, an output end of the first optocoupler is electrically connected to the third end of the switch protection unit, and an anode of the third voltage regulator tube is electrically connected to a positive electrode of the input power supply.

12. The protection circuit for a direct current power port as claimed in any one of claims 4 to 8, wherein the soft-start switch unit includes a second MOS transistor, a fourth voltage regulator transistor, a fifth voltage regulator transistor, and a first variable resistor, a gate of the second MOS transistor is connected to a cathode of the fifth voltage regulator transistor and is configured to access a driving signal of the second MOS transistor, a drain of the second MOS transistor is electrically connected to a cathode of the fourth voltage regulator transistor, one end of the first variable resistor, and a cathode of the power output port, respectively, and a source of the second MOS transistor is electrically connected to an anode of the fourth voltage regulator transistor, an anode of the fifth voltage regulator transistor, the other end of the first variable resistor, and a second end of the anti-reverse switch unit, respectively.

13. A power supply device characterized by comprising: the dc power port protection circuit of any one of claims 1-12.