Unidirectional voltage protection circuit, power supply and electronic equipment

Abstract

The utility model provides a unidirectional voltage protection circuit, a power supply and electronic equipment. The circuit comprises a detection module used for generating a control signal according to whether the voltage of a power supply is smaller than a preset low-voltage threshold and sending the control signal to a switch module; the switch module comprises a first switch tube, a second switch tube and a third switch tube; when the voltage of the power supply is smaller than a preset low-voltage threshold value, the first switching tube is cut off, so that the second switching tube and the third switching tube are cut off, and an open circuit is formed between the power supply and the electronic equipment. The unidirectional voltage protection circuit has the following advantages: when the voltage of the input end is lower than the preset low-voltage threshold value, the abnormality of the input voltage of the power supply can be detected, and then the connection between the power supply and the electronic equipment can be immediately and automatically cut off; the voltage and the current can prevent the voltage and the current of the output end interface from flowing back to the input end interface. According to the circuit, the detectable voltage is low, the error is small, and the circuit is stable and reliable.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply technical field, concretely relates to one -way voltage protection circuit, power supply and electronic equipment. BACKGROUND

[0002] When using electronic equipment in some special areas (such as gas explosion dangerous area and dust explosion dangerous area etc.), the peripheral interface of electronic equipment needs to be prevented from electrifying, or the explosion risk such as spark generated by rubbing with combustible gas / chemicals is prevented.In the above-mentioned environment, the voltage of the output end of the power supply is not allowed to be conducted to the input end.The overvoltage protection IC (integrated circuit) commonly used at present can realize the protection from the input end to the output end of the power supply when detecting that the voltage is too low, that is, no voltage is output to the output end.But the above-mentioned existing overvoltage protection IC has the following technical defects: 1) the voltage of the output end may still be conducted to the input end;2) the detectable voltage value of this kind of overvoltage protection IC is high, and the error is large, which is not suitable for some circuits with special requirements on voltage and current. SUMMARY

[0003] The technical problem solved by the utility model is how to prevent the voltage of the output end of the overvoltage protection IC from flowing back to the input end.The utility model provides a one-way voltage protection circuit, a power supply and an electronic equipment.

[0004] According to the first aspect, a one-way voltage protection circuit is provided in an embodiment, which is connected between a power supply and an electronic equipment.The one-way voltage protection circuit comprises:

[0005] A detection module is used to generate a corresponding control signal according to whether the voltage of the power supply is less than a preset low voltage threshold, and send the control signal to the switch module;

[0006] The switch module comprises a first switch tube, a second switch tube and a third switch tube; wherein the control end of the first switch tube is used to receive the control signal, the high potential end of the first switch tube is electrically connected with the control end of the second switch tube and the control end of the third switch tube, the low potential end of the first switch tube is grounded, the low potential end of the second switch tube is electrically connected with the positive electrode of the power supply, the high potential end of the second switch tube and the high potential end of the third switch tube are both electrically connected with the high potential end of the first switch tube, and the low potential end of the third switch tube is electrically connected with the electronic equipment; wherein if the voltage of the power supply is not less than the preset low voltage threshold, the first switch tube is turned on so that the second switch tube and the third switch tube are both turned on, so that a path is formed between the power supply and the electronic equipment; otherwise, the first switch tube is turned off so that the second switch tube and the third switch tube are both turned off, so that a circuit is formed between the power supply and the electronic equipment.

[0007] In an embodiment, the control signal is low when the voltage of the power supply is less than a preset low voltage threshold, and the control signal is high when the voltage of the power supply is not less than the preset low voltage threshold.

[0008] In an embodiment, the first switch tube is an NMOS tube, the control end, the high potential end and the low potential end of the first switch tube are the gate, the drain and the source of the NMOS tube in sequence, and the second switch tube and the third switch tube are PMOS tubes, the control end, the high potential end and the low potential end of the second switch tube and the third switch tube are the gate, the source and the drain of the PMOS tube in sequence.

[0009] In an embodiment, the switching module further comprises a fifth resistor, a sixth resistor and a seventh resistor, wherein the high potential end of the first switch tube is electrically connected with one end of the fifth resistor, one end of the sixth resistor and one end of the seventh resistor respectively, the other end of the fifth resistor is electrically connected with the control end of the second switch tube, the other end of the seventh resistor is electrically connected with the control end of the third switch tube, the low potential end of the second switch tube is electrically connected with the positive pole of the power supply, the low potential end of the third switch tube is electrically connected with the electronic device, and the other end of the sixth resistor is electrically connected with the high potential end of the second switch tube and the high potential end of the third switch tube respectively.

[0010] In an embodiment, the resistance value of the sixth resistor is greater than 10K, and the resistance value of the fifth resistor and the seventh resistor is between 9K and 11K.

[0011] In an embodiment, the detection module comprises a voltage comparator, wherein the third pin of the voltage comparator is electrically connected with the positive pole of the power supply, the second pin, the fourth pin and the sixth pin of the voltage comparator are grounded, the fifth pin of the voltage comparator is electrically connected with the positive pole of the power supply, and the first pin of the voltage comparator is electrically connected with the positive pole of the power supply and the control end of the first switch tube respectively, and the first pin of the voltage comparator is used for outputting the control signal to the first switch tube.

[0012] In an embodiment, the detection module further comprises a first resistor, a second resistor, a third resistor and a fourth resistor, wherein the third pin of the voltage comparator is electrically connected with one end of the first resistor and one end of the second resistor respectively, the other end of the first resistor is electrically connected with the positive pole of the power supply, the other end of the second resistor is grounded, the first pin of the voltage comparator is electrically connected with one end of the third resistor and the control end of the first switch tube respectively, the other end of the third resistor is electrically connected with the positive pole of the power supply and one end of the fourth resistor respectively, and the other end of the fourth resistor is electrically connected with the fifth pin of the voltage comparator.

[0013] In an embodiment, the unidirectional voltage protection circuit further comprises a surge protection diode, wherein the surge protection diode is arranged between the power supply and the detection module, one end of the surge protection diode is electrically connected to the positive pole of the power supply, and the other end of the surge protection diode is grounded.

[0014] According to the second aspect, in an embodiment, there is provided a power supply comprising the unidirectional voltage protection circuit of any of the embodiments herein.

[0015] According to the third aspect, in an embodiment, there is provided an electronic device comprising the unidirectional voltage protection circuit of any of the embodiments herein.

[0016] The beneficial effects of the present application are:

[0017] The unidirectional voltage protection circuit of the present application comprises a detection module for generating a control signal and sending the control signal to a switch module according to whether the voltage of the power supply is less than a preset low voltage threshold; the switch module comprises a first switch tube, a second switch tube and a third switch tube; the high potential end of the first switch tube is electrically connected to the control end of the second switch tube and the control end of the third switch tube, the low potential end of the first switch tube is grounded, the low potential end of the second switch tube is electrically connected to the positive pole of the power supply, the high potential end of the second switch tube and the high potential end of the third switch tube are both electrically connected to the high potential end of the first switch tube, and the low potential end of the third switch tube is electrically connected to the electronic device; when the voltage of the power supply is less than the preset low voltage threshold, the first switch tube is turned off so that the second switch tube and the third switch tube are both turned off, so as to form an open circuit between the power supply and the electronic device; wherein the second switch tube and the third switch tube are used to prevent the voltage and current at the output end of the circuit from flowing back to the input end. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Structure diagram of the unidirectional voltage protection circuit of an embodiment. DETAILED DESCRIPTION

[0019] The utility model will be further described in detail below by means of specific implementation and the drawings. In different embodiments, similar elements are associated with similar element labels. In the following embodiments, many details are described to make the application better understood. However, those skilled in the art can easily realize that some features can be omitted in different cases, or replaced by other elements, materials or methods. In some cases, some operations related to the application are not shown or described in the specification to avoid the core part of the application being overwhelmed by too much description, and detailed description of these related operations is not necessary for those skilled in the art, and they can fully understand the related operations according to the description in the specification and general technical knowledge in the art.

[0020] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate way to form various embodiments. At the same time, the steps or actions in the method description can also be sequentially adjusted or adjusted in a way that is obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clear description of a certain embodiment, and do not mean the necessary sequence, unless otherwise stated that a certain sequence must be followed.

[0021] The serial numbers of components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and have no sequence or technical meaning. Unless otherwise specified, "connection" and "coupling" in this application include direct and indirect connection (coupling).

[0022] The technical solutions of the application will be described in detail below in combination with embodiments.

[0023] The application provides a one-way voltage protection circuit for connecting between a power supply and an electronic device.

[0024] In some embodiments, please refer to Figure 1 VCC_IN and GND1 both represent the input interface of the circuit; VCC_OUT and GND2 both represent the output interface of the circuit. The one-way voltage protection circuit comprises:

[0025] The detection module 100 is used to generate a corresponding control signal according to whether the voltage of the power supply is less than a preset low voltage threshold, and send the control signal to the switch module 200;

[0026] The switch module 200 comprises a first switch tube D3, a second switch tube D1 and a third switch tube D2; wherein the control end of the first switch tube D3 is configured to receive the control signal, the high potential end of the first switch tube D3 is electrically connected with the control end of the second switch tube D1 and the control end of the third switch tube D2, the low potential end of the first switch tube D3 is grounded, the low potential end of the second switch tube D1 is electrically connected with the positive pole of the power supply, the high potential end of the second switch tube D1 and the high potential end of the third switch tube D2 are electrically connected with the high potential end of the first switch tube D3, and the low potential end of the third switch tube D2 is electrically connected with the electronic device; wherein if the voltage of the power supply is not less than a preset low voltage threshold, the first switch tube D3 is turned on so that the second switch tube D1 and the third switch tube D2 are both turned on, so that a path is formed between the power supply and the electronic device; otherwise, the first switch tube D3 is turned off so that the second switch tube D1 and the third switch tube D2 are both turned off, so that a circuit is formed between the power supply and the electronic device.

[0027] The specific size of the preset low voltage threshold can be determined by the person skilled in the art according to actual needs, for example, the preset low voltage threshold can be 400mV.

[0028] In some embodiments, when the voltage of the power supply is less than the preset low voltage threshold, the control signal is low; when the voltage of the power supply is not less than the preset low voltage threshold, the control signal is high. The control signal can also be determined by the person skilled in the art according to actual needs.

[0029] In some embodiments, the first switch tube D3 is an NMOS tube, and the control end, the high potential end and the low potential end of the first switch tube are the gate, the drain and the source of the NMOS tube in sequence; the second switch tube D1 and the third switch tube D2 are both PMOS tubes, and the control end, the high potential end and the low potential end of the second switch tube D1 and the third switch tube D2 are the gate, the source and the drain of the PMOS tube in sequence.

[0030] It can be understood that when the gate-source voltage (Vgs) of the first switch tube D3 is greater than the threshold voltage (Vth), the first switch tube D3 is turned on, and then the gate-source voltage (Vgs) of the second switch tube D1 and the third switch tube D2 is pulled down respectively. Since the second switch tube D1 and the third switch tube D2 are PMOS tubes, when the gate-source voltage (Vgs) of the second switch tube D1 or the third switch tube D2 is less than the threshold voltage (Vth), the second switch tube D1 or the third switch tube D2 is turned on; when the gate-source voltage (Vgs) of the second switch tube D1 or the third switch tube D2 is greater than the threshold voltage (Vth), the second switch tube D1 or the third switch tube D2 is turned off, and there is no voltage and current output from the input interface to the output interface.

[0031] In some embodiments, when the first switch tube D3 is an NMOS tube, the control signal output from the first pin of the voltage comparator U1 is used to control the first switch tube D3 to be turned on or turned off.

[0032] It can be understood that when the control signal is high, the first switch tube D3 is turned on, the second switch tube D1 and the third switch tube D2 are both turned on, and the voltage at the output interface is equal to the voltage at the input interface; when the control signal is low, the first switch tube D3 is turned off, the second switch tube D1 and the third switch tube D2 are both turned off, and the voltage at the output interface is equal to 0V; when the output interface needs to be debugged, the second switch tube D1 and the third switch tube D2 are turned off to prevent the voltage and current at the output interface from being connected to the input interface. This is because the commonly used PMOS tube usually has a Schottky diode (body diode) inside. If only one PMOS tube (such as only the third switch tube D2 without the second switch tube D1) is used in the circuit, the voltage and current at the output interface may be connected to the input interface through the body diode of the third switch tube D2, i.e., the output interface and the input interface may not be completely disconnected.

[0033] In some embodiments, the first switch tube D3 can be an NPN type transistor. The second switch tube D1 and the third switch tube D2 can be PNP type transistors.

[0034] In some embodiments, the switching module 200 further includes a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The high potential end of the first switch tube D3 is electrically connected to one end of the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7. The other end of the fifth resistor R5 is electrically connected to the control end of the second switch tube D1. The other end of the seventh resistor R7 is electrically connected to the control end of the third switch tube D2. The low potential end of the second switch tube D1 is electrically connected to the positive pole of the power supply. The low potential end of the third switch tube D2 is electrically connected to the electronic device. The other end of the sixth resistor R6 is electrically connected to the high potential end of the second switch tube D1 and the high potential end of the third switch tube D2.

[0035] In some embodiments, preferably, the resistance value of the sixth resistor R6 is greater than 10K, so as to prevent the current limiting resistor from being too small when the circuit is working. The resistance value of the fifth resistor R5 and the seventh resistor R7 is between 9K and 11K. Preferably, the resistance value of the fifth resistor R5 and the seventh resistor R7 can be about 10K, so as to prevent the pins of the second switch tube D1 and the third switch tube D2 from being damaged by the instantaneous voltage being too high.

[0036] In some embodiments, the detection module 100 comprises a voltage comparator U1; wherein a third pin of the voltage comparator U1 is electrically connected to the positive pole of the power supply, a second pin, a fourth pin and a sixth pin of the voltage comparator U1 are grounded, a fifth pin of the voltage comparator U1 is electrically connected to the positive pole of the power supply, a first pin of the voltage comparator U1 is electrically connected to the positive pole of the power supply and the control end of the first switch tube D3 respectively, and the first pin of the voltage comparator U1 is used to output a control signal to the first switch tube D3. The third pin of the voltage comparator U1 is a voltage detection pin. Preferably, the model of the voltage comparator U1 can be TLV6713DDCR; wherein the high power voltage range of the voltage comparator is 1.8V to 36V, the adjustable threshold value can be as low as 400mV, the high threshold value accuracy is 0.25% (typical value), and the maximum is 0.75% in the working temperature range.

[0037] In some embodiments, the detection module 100 further comprises a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4; wherein the third pin of the voltage comparator U1 is electrically connected to one end of the first resistor R1 and one end of the second resistor R2 respectively, the other end of the first resistor R1 is electrically connected to the positive pole of the power supply, the other end of the second resistor R1 is grounded, the first pin of the voltage comparator U1 is electrically connected to one end of the third resistor R3 and the control end of the first switch tube D3 respectively, the other end of the third resistor R3 is electrically connected to the positive pole of the power supply and one end of the fourth resistor R4 respectively, and the other end of the fourth resistor R4 is electrically connected to the fifth pin of the voltage comparator U1. Wherein the first resistor R1 and the second resistor R2 are pull-up resistor and pull-down resistor respectively. The specific resistance value of the first resistor R1 and the second resistor R2 can be determined by the person skilled in the art according to the actual demand. The third resistor R3 and the fourth resistor R4 are current limiting resistors. The fourth resistor R4 is electrically connected to the fifth pin of the voltage comparator U1, which is used to supply power to the voltage comparator U1.

[0038] In some embodiments, since the first pin of the voltage comparator U1 is an OD gate circuit (a gate circuit with an open-drain output), and the first pin is electrically connected to the control end of the first switch tube D3, preferably, the resistance value of the third resistor R3 can be 100K. Since the power consumption current of the voltage comparator U1 during operation is about 10uA, preferably, the resistance value of the fourth resistor R4 is 100K. The voltage of VCC IN is output to the third pin of the voltage comparator U1 after being divided by the first resistor R1 and the second resistor R2. When the third pin of the voltage comparator U1 detects that the voltage of VCC IN exceeds the preset low voltage threshold of the voltage comparator U1, the first pin of the voltage comparator U1 outputs a high level; when the third pin of the voltage comparator U1 detects that the voltage of VCC IN is lower than the preset low voltage threshold, the first pin of the voltage comparator U1 outputs a low level.

[0039] In some embodiments, the unidirectional voltage protection circuit further comprises a surge protection diode D4; wherein the surge protection diode is arranged between the power supply and the detection module 100, one end (such as the anode) of the surge protection diode is electrically connected to the positive electrode of the power supply, and the other end (such as the cathode) of the surge protection diode is grounded. The function of the surge protection diode D4 is to prevent instantaneous surge high voltage from damaging the rear-end device.

[0040] The following is a brief description of the specific working process of the unidirectional voltage protection circuit in some embodiments: assuming that the model of the voltage comparator U1 is TLV6713DDCR, when the voltage detected by the third pin of the voltage comparator U1 is greater than 400mV, the first pin of the voltage comparator U1 outputs a high level, the first switch tube D3 is turned on, and the second switch tube D1 and the third switch tube D2 meet the conduction condition, so that the voltage and current can be normally output from the above-mentioned input terminal interface to the output terminal interface; when the voltage detected by the third pin of the voltage comparator U1 is less than 400mV, the first pin of the voltage comparator U1 outputs a low level, the first switch tube D3 is cut off, and the second switch tube D1 and the third switch tube D2 do not meet the conduction condition, so that a circuit is formed between the above-mentioned input terminal interface and the output terminal interface, i.e. the voltage and current cannot be normally output from the above-mentioned input terminal interface to the output terminal interface.

[0041] As can be seen, in some embodiments, the detection accuracy of the voltage comparator U1 of the one-way voltage protection circuit is high, and the detectable voltage is also small (e.g., 1.8V to 36V), so the one-way voltage protection circuit can detect a lower voltage (e.g., the detectable voltage can be lower than 500mV), has a small error, and is stable and reliable. In addition, the first resistor R1 and the second resistor R2 in the one-way voltage protection circuit usually have a large resistance value, so the loss current is small. The one-way voltage protection circuit is composed of multiple separable devices (e.g., the voltage comparator U1, the first resistor R1, the second resistor R2, and the first switch tube D3), and the optimal performance of the circuit can be achieved by adjusting the corresponding devices.

[0042] As can be seen, in some embodiments, the one-way voltage protection circuit of the present application has the following advantages: 1) when the voltage at the input end thereof is lower than a preset low voltage threshold, the one-way voltage protection circuit can detect an abnormality of the power supply input voltage, and then immediately automatically disconnect the connection between the power supply and the electronic device, i.e., at this time, the risk of output voltage and current of the one-way voltage protection circuit is prevented; 2) the voltage and current can only be transmitted from the above-mentioned input end interface to the output end interface of the one-way voltage protection circuit in one direction, and cannot be transmitted from the output end interface to the input end interface, i.e., the voltage and current of the output end interface can be effectively prevented from flowing back to the input end interface, so that an accident of safety regulations is prevented. When far away from a dangerous area, the one-way voltage protection circuit can be externally connected to a power supply, and can supply power or charge an electronic device, etc.

[0043] The above is some description of the one-way voltage protection circuit. In some embodiments of the present application, a power supply comprising the one-way voltage protection circuit of any one of the embodiments herein is also disclosed.

[0044] In some embodiments of the present application, an electronic device comprising the one-way voltage protection circuit of any one of the embodiments herein is also disclosed.

[0045] The various exemplary embodiments are described herein. However, those skilled in the art will recognize that changes and modifications can be made to the exemplary embodiments without departing from the scope hereof. For example, the various operational steps and components for carrying out the operational steps can be implemented differently depending on the particular application or considerations associated with the operation of the system (e.g., one or more steps can be deleted, modified, or combined with other steps).

[0046] In the above embodiments, all or part of the above embodiments can be implemented by software, hardware, firmware or any combination thereof. In addition, as understood by those skilled in the art, the principles herein can be reflected in a computer program product on a computer readable storage medium preloaded with computer readable program code. Any tangible, non-transitory computer readable storage medium can be used, including magnetic storage devices (hard disk, floppy disk, etc.), optical storage devices (CD-ROM, DVD, Blu Ray disc, etc.), flash memory and / or the like. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to form a machine, so that these instructions executed on the computer or other programmable data processing apparatus can generate a device that implements the specified function. These computer program instructions can also be stored in a computer readable storage medium, which can instruct the computer or other programmable data processing apparatus to operate in a specific way, so that the instructions stored in the computer readable storage medium can form a manufactured product, including an implementation device that implements the specified function. Computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so as to execute a series of operation steps on the computer or other programmable data processing apparatus to generate a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus can provide steps for implementing the specified function.

[0047] Although the principles herein have been shown in various embodiments, many modifications in structure, arrangement, proportions, elements, materials, and components specially adapted to specific environments and operational requirements can be used without departing from the principles and scope of the present disclosure. The above modifications and other changes or modifications will be included within the scope of the principles herein.

[0048] The foregoing detailed description has been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of the present disclosure. Accordingly, the present disclosure is intended to be illustrative and not limiting, and all such modifications are intended to be included within the scope of the present disclosure. Also, advantages, other advantages, and solutions to problems have been described above as related to various embodiments. However, the benefits, advantages, solutions to problems and any element(s) that can cause these to occur, or to become more pronounced, are not to be construed as critical, required or essential features of the present disclosure. The terms "comprises", "comprising", or any other variations thereof, as used in the herein are of a non-exclusive inclusion, such that a process, method, article or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, system, article or apparatus. In addition, the terms "coupled" and any other variations thereof, as used herein, refer to physical connection, electrical connection, magnetic connection, optical connection, communicative connection, functional connection and / or any other connection.

[0049] One skilled in the art will recognize that the foregoing preferred embodiments can be readily substituted for one another, and many changes can be made to the foregoing embodiments without departing from the spirit and scope of the present application. Accordingly, the scope of the present application should be determined by the following claims.

Claims

1. A unidirectional voltage protection circuit, connected between a power supply and electronic equipment, characterized in that, The application relates to a power supply protection circuit. The detection module is used for generating a corresponding control signal according to whether the voltage of the power supply is less than a preset low-voltage threshold, and sending the control signal to the switch module. The switch module comprises a first switch tube, a second switch tube and a third switch tube; the control end of the first switch tube is used for receiving the control signal; the high-potential end of the first switch tube is electrically connected with the control end of the second switch tube and the control end of the third switch tube; the low-potential end of the first switch tube is grounded; the low-potential end of the second switch tube is electrically connected with the positive pole of the power supply; the high-potential end of the second switch tube and the high-potential end of the third switch tube are both electrically connected with the high-potential end of the first switch tube; and the low-potential end of the third switch tube is electrically connected with an electronic device. If the voltage of the power supply is not less than the preset low-voltage threshold, the first switch tube is turned on so that the second switch tube and the third switch tube are both turned on, so that a passage is formed between the power supply and the electronic device; otherwise, the first switch tube is turned off so that the second switch tube and the third switch tube are both turned off, so that a circuit is formed between the power supply and the electronic device.

2. The unidirectional voltage protection circuit of claim 1, wherein, When the voltage of the power supply is less than the preset low-voltage threshold, the control signal is low; when the voltage of the power supply is not less than the preset low-voltage threshold, the control signal is high.

3. The unidirectional voltage protection circuit of claim 2, wherein, The first switch tube is an NMOS tube, the control end, the high-potential end and the low-potential end of the first switch tube are the gate, the drain and the source of the NMOS tube in sequence; the second switch tube and the third switch tube are both PMOS tubes, the control end, the high-potential end and the low-potential end of the second switch tube and the third switch tube are the gate, the source and the drain of the PMOS tube in sequence.

4. The unidirectional voltage protection circuit of claim 1, wherein, The switch module further comprises a fifth resistor, a sixth resistor and a seventh resistor; the high-potential end of the first switch tube is electrically connected with one end of the fifth resistor, one end of the sixth resistor and one end of the seventh resistor in sequence; the other end of the fifth resistor is electrically connected with the control end of the second switch tube; the other end of the seventh resistor is electrically connected with the control end of the third switch tube; the low-potential end of the second switch tube is electrically connected with the positive pole of the power supply; the low-potential end of the third switch tube is electrically connected with the electronic device; and the other end of the sixth resistor is electrically connected with the high-potential end of the second switch tube and the high-potential end of the third switch tube in sequence.

5. The unidirectional voltage protection circuit of claim 4, wherein, The resistance of the sixth resistor is greater than 10K, and the resistance of the fifth resistor and the seventh resistor is between 9K and 11K.

6. The unidirectional voltage protection circuit of claim 1, wherein, The detection module comprises a voltage comparator; the third pin of the voltage comparator is electrically connected with the positive pole of the power supply; the second pin, the fourth pin and the sixth pin of the voltage comparator are all grounded; the fifth pin of the voltage comparator is electrically connected with the positive pole of the power supply; and the first pin of the voltage comparator is electrically connected with the positive pole of the power supply and the control end of the first switch tube in sequence, and is used for outputting the control signal to the first switch tube.

7. The unidirectional voltage protection circuit of claim 6, wherein, The detection module further comprises a first resistor, a second resistor, a third resistor and a fourth resistor; wherein a third pin of the voltage comparator is electrically connected with one end of the first resistor and one end of the second resistor respectively, the other end of the first resistor is electrically connected with the positive pole of the power supply, the other end of the second resistor is grounded, a first pin of the voltage comparator is electrically connected with one end of the third resistor and the control end of the first switch tube respectively, the other end of the third resistor is electrically connected with the positive pole of the power supply and one end of the fourth resistor respectively, and the other end of the fourth resistor is electrically connected with a fifth pin of the voltage comparator.

8. The unidirectional voltage protection circuit of claim 1, wherein, The unidirectional voltage protection circuit further comprises a surge protection diode; wherein the surge protection diode is arranged between the power supply and the detection module, one end of the surge protection diode is electrically connected with the positive pole of the power supply, and the other end of the surge protection diode is grounded.

9. A power supply, characterized by, The unidirectional voltage protection circuit comprises the detection module.

10. An electronic device, comprising: The unidirectional voltage protection circuit comprises the detection module.

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