A protective circuit and electronic equipment

Abstract

The embodiments of the present application provide a protection circuit and an electronic device, wherein the protection circuit includes: a power port, an anti-surge circuit, an anti-reverse voltage circuit and an anti-overvoltage circuit, wherein the power port is connected to the anti-surge circuit, the anti-surge circuit is connected to a first ground line, the anti-surge circuit is used to suppress the transient voltage of the protection circuit, the anti-reverse voltage circuit is connected to the power port and is connected in parallel with the anti-surge circuit, the anti-reverse voltage circuit is also connected to a second ground line, the anti-reverse voltage circuit is used to eliminate the negative voltage of the protection circuit, the anti-overvoltage circuit is connected to the power port and is connected in parallel with the anti-reverse voltage circuit and the anti-overvoltage circuit respectively, the anti-overvoltage circuit is also connected to the second ground line, and the anti-overvoltage circuit is used to stop the output voltage when the input voltage of the anti-overvoltage circuit is greater than a threshold voltage, so as to improve the protection effect of the protection circuit.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of circuits, and in particular, to a protection circuit and electronic equipment. Background Art

[0002] In order to prevent the circuits and electronic components in electronic equipment from being potentially damaged, a protection circuit is usually designed in the circuit of the electronic equipment. The protection circuit can be used to protect the circuits and electronic components of the electronic equipment to improve the reliability and life of the electronic equipment.

[0003] At present, the protection circuit can be used for overvoltage protection, short circuit protection, etc. In order to realize the function of the protection circuit, there are various protection elements. For example, the protection element may include a transient suppression diode, a fuse, a thermistor, a metal oxide varistor, etc. Developers can determine the protection circuit according to the circuit structure in the electronic device.

[0004] In the above process, the designed protection circuit may only realize one protection function, resulting in poor protection effect of the protection circuit. Utility Model Content

[0005] The embodiments of the present application provide a protection circuit and an electronic device to solve the defect that the protection circuit designed in the prior art may only realize one protection function, resulting in poor protection effect of the protection circuit.

[0006] In a first aspect, an embodiment of the present application provides a protection circuit, which is applied to an electronic device, and includes: a power port, a surge protection circuit, a reverse voltage protection circuit, and an overvoltage protection circuit;

[0007] The power port is connected to the surge protection circuit, the surge protection circuit is connected to the first ground line, and the surge protection circuit is used to suppress the transient voltage of the protection circuit;

[0008] The anti-reverse voltage circuit is connected to the power port and connected in parallel with the anti-surge circuit. The anti-reverse voltage circuit is also connected to the second ground line. The anti-reverse voltage circuit is used to eliminate the negative voltage of the protection circuit.

[0009] The overvoltage protection circuit is connected to the power port and is connected in parallel with the reverse voltage protection circuit and the overvoltage protection circuit respectively. The overvoltage protection circuit is also connected to the second ground line. The overvoltage protection circuit is used to stop the output voltage when the input voltage of the overvoltage protection circuit is greater than the threshold voltage.

[0010] In a possible design, the anti-reverse voltage circuit includes a first resistor, a second resistor, a field effect transistor and a capacitor;

[0011] A first end of the first resistor is connected to the power port, a second end of the first resistor is connected to a first end of the second resistor, and a second end of the second resistor is connected to a second ground line;

[0012] The field effect tube is respectively connected to the second end of the first resistor, the second end of the second resistor and the surge protection circuit;

[0013] The first end of the capacitor is connected to the power port, and the second end of the capacitor is connected to the second ground line.

[0014] In a possible design, the field effect transistor is an N-channel field effect transistor, and the N-channel field effect transistor includes a gate, a source, and a drain;

[0015] The gate is connected to the second end of the first resistor, the source is connected to the second end of the second resistor, and the drain is connected to the surge protection circuit.

[0016] In a possible design, the first resistor is smaller than the second resistor.

[0017] In a possible design, component parameters corresponding to the first resistor, the second resistor, the field effect transistor, and the capacitor are determined according to the overvoltage protection circuit.

[0018] In one possible design, the surge protection circuit includes a transient suppression diode;

[0019] The power port is connected to a first end of the transient voltage suppression diode, and a second end of the transient voltage suppression diode is connected to a first ground line.

[0020] In a possible design, the diode type of the transient suppression diode is determined according to the installation location of the electronic device, power adapter parameters and rated voltage.

[0021] In a possible design, the overvoltage protection circuit includes an overvoltage protection chip; the overvoltage protection chip includes an input terminal, an output terminal and a plurality of ground terminals;

[0022] The input end of the overvoltage protection chip is connected to the power port, the output end of the overvoltage protection chip is connected to the subsequent circuit of the electronic device, and the multiple grounding ends are connected to the second ground wire.

[0023] In one possible design, the chip type of the overvoltage protection chip is determined according to the surge protection circuit and the rated voltage of the electronic device.

[0024] In a second aspect, an embodiment of the present application provides an electronic device, comprising the protection circuit as described in the first aspect.

[0025] The embodiment of the present application provides a protection circuit and an electronic device, wherein the protection circuit includes: a power port, an anti-surge circuit, an anti-reverse voltage circuit and an anti-overvoltage circuit, wherein the power port is connected to the anti-surge circuit, the anti-surge circuit is connected to the first ground line, the anti-surge circuit is used to suppress the transient voltage of the protection circuit, the anti-reverse voltage circuit is connected to the power port and is connected in parallel with the anti-surge circuit, the anti-reverse voltage circuit is also connected to the second ground line, the anti-reverse voltage circuit is used to eliminate the negative voltage of the protection circuit, the anti-overvoltage circuit is connected to the power port and is connected in parallel with the anti-reverse voltage circuit and the anti-overvoltage circuit respectively, the anti-overvoltage circuit is also connected to the second ground line, and the anti-overvoltage circuit is used to stop the output voltage when the input voltage of the anti-overvoltage circuit is greater than the threshold voltage. In this way, by determining the structures of the anti-surge circuit and the anti-overvoltage circuit, the protection circuit can be compatible with the anti-reverse voltage and anti-overvoltage protection when preventing surges, thereby improving the protection effect of the protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the structure of a circuit in an electronic device provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the structure of a protection circuit provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of the structure of another protection circuit provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of the structure of another protection circuit provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0032] Reference numerals:

[0033] 101-power port; 102-protection circuit; 103-post-stage circuit; 202-surge protection circuit; 203-reverse voltage protection circuit; 204-overvoltage protection circuit; 205-first ground wire; 206-second ground wire; 301-first resistor; 302-second resistor; 303-field effect transistor; 304-capacitor; 401-transient suppression diode; 402-overvoltage protection chip. DETAILED DESCRIPTION

[0034] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0035] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] In the present application, the term "include" and its variations may refer to non-restrictive inclusion; the term "or" and its variations may refer to "and / or". The terms "first", "second", etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In the present application, "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previously associated objects are in an "or" relationship.

[0037] In order to prevent the circuits and electronic components in electronic equipment from being potentially damaged, a protection circuit is usually designed in the circuit of the electronic equipment. The protection circuit can be used to protect the circuits and electronic components of the electronic equipment to improve the reliability and life of the electronic equipment.

[0038] Figure 1 This is a schematic diagram of a circuit structure in an electronic device provided in an embodiment of the present application. Figure 1 , Figure 1 The electronic device may include an electronic device, and the circuit structure of the electronic device may include a power port 101 , a protection circuit 102 and a subsequent circuit 103 .

[0039] The power port 101 can be used to connect a power adapter or a power cord to provide the power supply required by the device. The power port 101 can be a specific shape and specification to ensure that only a compatible power adapter can be connected to the device. For example, the power port 101 can be an interface with a rated voltage of DC 12V.

[0040] The protection circuit 102 can be used to protect the circuits and electronic components of the electronic device to improve the reliability and life of the electronic device. The protection circuit 102 can be used for overvoltage protection, short circuit protection, etc. In order to realize the function of the protection circuit 102, there are a variety of protection elements. For example, the protection element may include a transient suppression diode, a fuse, a thermistor, a metal oxide varistor, etc.

[0041] The post-stage circuit 103 can be used to implement the design function of the electronic device to ensure that the electronic device works stably and reliably. The post-stage circuit 103 may include a power amplifier, an output buffer, a filter, a driving circuit, and the like.

[0042] In the related art, the protection circuit can be used for overvoltage protection, short circuit protection, etc. In order to realize the function of the protection circuit, there are various protection elements. For example, the protection element may include a transient suppression diode, a fuse, a thermistor, a metal oxide varistor, etc. The developer can determine the protection circuit according to the circuit structure in the electronic device.

[0043] In the above process, the designed protection circuit may only realize one protection function, resulting in poor protection effect of the protection circuit.

[0044] In order to solve the above technical problems, an embodiment of the present application provides a protection circuit. By determining the connection relationship between the surge protection circuit, the reverse voltage protection circuit and the overvoltage protection circuit, the protection circuit can be compatible with the reverse voltage protection and the overvoltage protection when preventing surges, thereby improving the protection effect of the protection circuit.

[0045] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0046] Figure 2 This is a schematic diagram of a protection circuit provided in an embodiment of the present application. Figure 2 , the protection circuit is applied to electronic equipment, the protection circuit includes: a power port 101, a surge protection circuit 202, a reverse voltage protection circuit 203 and an overvoltage protection circuit 204;

[0047] The power port 101 is connected to the surge protection circuit 202, and the surge protection circuit 202 is connected to the first ground line 205. The surge protection circuit 202 is used to suppress the transient voltage of the protection circuit;

[0048] The reverse voltage protection circuit 203 is connected to the power port 101 and is connected in parallel to the surge protection circuit 202. The reverse voltage protection circuit 203 is also connected to the second ground line 206. The reverse voltage protection circuit 203 is used to eliminate the negative voltage of the protection circuit.

[0049] The overvoltage protection circuit 204 is connected to the power port 101 and is connected in parallel with the reverse voltage protection circuit 203 and the overvoltage protection circuit 204 respectively. The overvoltage protection circuit 204 is also connected to the second ground line 206. The overvoltage protection circuit 204 is used to stop the output voltage when the input voltage of the overvoltage protection circuit 204 is greater than the threshold voltage.

[0050] The surge protection circuit 202 can be used to detect whether the voltage value corresponding to the input voltage signal of the power port 101 is greater than the differential mode surge voltage value. If so, the input voltage signal can be converted into a clamping voltage signal; if not, the input voltage signal can be output.

[0051] The differential mode surge voltage value may indicate the voltage value corresponding to the maximum transient overvoltage that the protection circuit can withstand between the external power supply and the power port of the electronic device.

[0052] Transient overvoltages can be transient voltage spikes or pulses caused by external factors.

[0053] External factors can be lightning strikes, power system switching, load changes, etc.

[0054] The anti-reverse voltage circuit 203 can be used to detect whether the voltage value corresponding to the input voltage signal or the voltage value corresponding to the clamping voltage signal is less than the negative voltage limit. If so, the input voltage signal or the clamping voltage signal can be reverse-voltage protected to obtain a forward voltage signal; if not, the input voltage signal or the clamping voltage signal can be output.

[0055] The negative voltage limit may indicate the lowest voltage value that the protection circuit can withstand while functioning normally or without being damaged.

[0056] The overvoltage protection circuit 204 can be used to detect whether the voltage value corresponding to the input voltage signal, the voltage value corresponding to the clamping voltage signal or the voltage value corresponding to the forward voltage signal is greater than the threshold voltage value. If so, the input voltage signal, the clamping voltage signal or the forward voltage signal can be protected from overvoltage; if not, the voltage is output to the subsequent circuit.

[0057] The threshold voltage value can be used to indicate the voltage value at which the overvoltage protection chip starts to activate the protection mechanism.

[0058] The first ground line and the second ground line are not connected.

[0059] In this embodiment, the protection circuit includes: a power port, an anti-surge circuit, an anti-reverse voltage circuit and an anti-overvoltage circuit. The power port is connected to the anti-surge circuit, the anti-surge circuit is connected to the first ground line, the anti-surge circuit is used to suppress the transient voltage of the protection circuit, the anti-reverse voltage circuit is connected to the power port and connected in parallel with the anti-surge circuit, the anti-reverse voltage circuit is also connected to the second ground line, the anti-reverse voltage circuit is used to eliminate the negative voltage of the protection circuit, the anti-overvoltage circuit is connected to the power port and connected in parallel with the anti-reverse voltage circuit and the anti-overvoltage circuit respectively, the anti-overvoltage circuit is also connected to the second ground line, and the anti-overvoltage circuit is used to stop the output voltage when the input voltage of the anti-overvoltage circuit is greater than the threshold voltage. In this way, the connection relationship between the anti-surge circuit, the anti-reverse voltage circuit and the anti-overvoltage circuit is determined, so that the protection circuit can be compatible with the anti-reverse voltage and anti-overvoltage protection when preventing surges, thereby improving the protection effect of the protection circuit.

[0060] Below, in Figure 2 Based on Figure 3 , the anti-reverse voltage circuit is further explained.

[0061] For example, Figure 3 This is a schematic diagram of another protection circuit provided in an embodiment of the present application. Figure 3 , Figure 3 A reverse voltage protection circuit may be included, and the reverse voltage protection circuit may include a first resistor 301 , a second resistor 302 , a field effect transistor 303 , and a capacitor 304 .

[0062] A first end of the first resistor 301 is connected to the power port 101 , a second end of the first resistor 301 is connected to a first end of the second resistor 302 , and a second end of the second resistor 302 is connected to the second ground line 206 ;

[0063] The field effect transistor 303 is respectively connected to the second end of the first resistor 301, the second end of the second resistor 302 and the surge protection circuit 202;

[0064] A first end of the capacitor 304 is connected to the power port 101 , and a second end of the capacitor 304 is connected to the second ground line 206 .

[0065] Among them, the first resistor is smaller than the second resistor. When the voltage value corresponding to the detected input voltage signal or the voltage value corresponding to the clamped voltage signal is smaller than the negative voltage limit, since the first resistor is smaller than the second resistor, the field effect tube is turned off, and the negative voltage disappears after passing through the first resistor, the second resistor, the capacitor and the second ground wire. When the voltage value corresponding to the detected input voltage signal or the voltage value corresponding to the clamped voltage signal is greater than the negative voltage limit, the field effect tube is turned on, and there is no need to eliminate the negative voltage, and the voltage can be transmitted normally to the overvoltage protection chip.

[0066] In one embodiment, the field effect transistor is an N-channel field effect transistor, and the N-channel field effect transistor includes a gate, a source, and a drain;

[0067] The gate is connected to the second end of the first resistor, the source is connected to the second end of the second resistor, and the drain is connected to the surge protection circuit.

[0068] When the voltage value corresponding to the detected input voltage signal or the voltage value corresponding to the clamped voltage signal is less than the negative voltage limit, since the first resistor is less than the second resistor, the gate of the corresponding field effect tube is less than the source of the field effect tube, and the field effect tube is turned off. When the voltage value corresponding to the detected input voltage signal or the voltage value corresponding to the clamped voltage signal is greater than the negative voltage limit, the gate of the field effect tube is greater than the source of the field effect tube, and the field effect tube is turned on.

[0069] In one implementation, component parameters corresponding to the first resistor 301 , the second resistor 302 , the field effect transistor 303 , and the capacitor 304 may be determined according to an overvoltage protection circuit.

[0070] Optionally, the overvoltage protection circuit may include an overvoltage protection chip, and component parameters corresponding to the first resistor 301, the second resistor 302, the field effect transistor 303 and the capacitor 304 are determined according to the overvoltage protection chip, the chip type and the rated voltage value.

[0071] The rated voltage value is determined based on the device information of the electronic equipment.

[0072] Optionally, the component parameters corresponding to the first resistor, the second resistor, the field effect transistor and the capacitor can be determined in the following manner: determine the negative voltage limit of the protection circuit according to the chip type; obtain a first mapping relationship, the first mapping relationship including multiple negative voltage limits to be selected, multiple resistance values ​​corresponding to each negative voltage limit to be selected, and a capacitance value corresponding to each negative voltage limit to be selected; determine the component parameters of the multiple resistors and the component parameters of the capacitor according to the negative voltage limit and the first mapping relationship; determine the component parameters of the field effect transistor according to the rated voltage value.

[0073] In this embodiment, the first end of the first resistor is connected to the power supply port, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the second ground line, the field effect transistor is respectively connected to the second end of the first resistor, the second end of the second resistor and the surge protection circuit, the first end of the capacitor is connected to the power supply port, and the second end of the capacitor is connected to the second ground line. In this way, the structure of the anti-reverse voltage circuit is determined to achieve that the protection circuit can be compatible with anti-reverse voltage and anti-overvoltage protection when preventing surges, thereby improving the protection effect of the protection circuit.

[0074] Below, in Figure 3 Based on Figure 4, the surge protection circuit and overvoltage protection circuit are explained respectively.

[0075] For example, Figure 4 This is a schematic diagram of another protection circuit provided in the embodiment of the present application. Figure 4 , Figure 4 The protection circuit may include a reverse voltage protection circuit, which includes: a power port 101, a surge protection circuit, a reverse voltage protection circuit and an overvoltage protection circuit. The reverse voltage protection circuit may refer to the above embodiment and will not be described in detail here. The surge protection circuit may include a transient suppression diode 401.

[0076] The power port is connected to a first end of the transient voltage suppressor diode 401 , and a second end of the transient voltage suppressor diode 401 is connected to a first ground line.

[0077] The transient voltage suppressor diode 401 can be used to detect whether the voltage value corresponding to the input voltage signal of the power port is greater than the differential mode surge voltage value.

[0078] Optionally, the diode type of the transient voltage suppressor diode 401 may be determined according to the installation location of the electronic device, the parameters of the power adapter, and the rated voltage.

[0079] Optionally, the diode type of the transient suppression diode can be determined in the following manner: determine the differential-mode surge voltage value of the transient suppression diode of the protection circuit according to the installation position; determine the packaging method of the transient suppression diode according to the differential-mode surge voltage value; determine the breakdown voltage value of the transient suppression diode according to the power supply adapter parameters; determine the diode type of the transient suppression diode according to the differential-mode surge voltage value, packaging method and breakdown voltage value.

[0080] There are multiple packaging methods to suit different application requirements and installation environments.

[0081] The packaging method may include a first packaging method, a second packaging method, a third packaging method, etc. The first packaging method may be applicable to medium-power transient suppression diodes. The second packaging method may be applicable to higher-power transient suppression diodes. The third packaging method may be applicable to high-power transient suppression diodes.

[0082] The breakdown voltage value may represent the voltage value at which the TVS diode begins to conduct and clamp the voltage.

[0083] The breakdown voltage value is higher than the normal operating voltage value of the electronic equipment.

[0084] In a possible implementation, the overvoltage protection circuit may include an overvoltage protection chip 402. The overvoltage protection chip 402 includes an input terminal, an output terminal, and a plurality of ground terminals.

[0085] The input end of the overvoltage protection chip 402 is connected to the power port, the output end of the overvoltage protection chip 402 is connected to the subsequent circuit of the electronic device, and the multiple grounding ends are connected to the second ground line.

[0086] In a possible implementation, the chip type of the overvoltage protection chip 402 may be determined according to the surge protection circuit and the rated voltage of the electronic device.

[0087] Optionally, the surge protection circuit may include a transient suppression diode, and the chip type of the overvoltage protection chip 402 may be determined according to the diode type of the transient suppression diode and the rated voltage of the electronic device.

[0088] Optionally, the chip type of the overvoltage protection chip can be determined in the following manner: determine the clamping voltage value of the transient suppression diode according to the diode type; determine the withstand voltage limit of the overvoltage protection chip of the protection circuit according to the clamping voltage value; determine the threshold voltage value of the overvoltage protection chip according to the rated voltage value; determine the chip type of the overvoltage protection chip according to the withstand voltage limit and the threshold voltage value.

[0089] The clamping voltage value may represent the maximum voltage value to which the TVS diode clamps the voltage when a transient event occurs.

[0090] The withstand voltage limit can be used to indicate the maximum voltage value that the overvoltage protection chip can withstand without being damaged or having its performance degraded.

[0091] The threshold voltage value can be used to indicate the voltage value at which the overvoltage protection chip starts to activate the protection mechanism.

[0092] In this embodiment, the surge protection circuit includes a transient suppression diode, the power port is connected to the first end of the transient suppression diode, the second end of the transient suppression diode is connected to the first ground line, and the overvoltage protection circuit includes an overvoltage protection chip; the overvoltage protection chip includes an input end, an output end and multiple grounding ends; the input end of the overvoltage protection chip is connected to the power port, the output end of the overvoltage protection chip is connected to the rear circuit of the electronic device, and the multiple grounding ends are connected to the second ground line. In this way, the structures of the surge protection circuit and the overvoltage protection circuit are determined to achieve that the protection circuit can be compatible with the reverse voltage protection and overvoltage protection when preventing surges, thereby improving the protection effect of the protection circuit.

[0093] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 5 , Figure 5 The protection circuit may include any one of the above embodiments.

[0094] In this embodiment, the protection effect of the electronic device is improved by providing the above protection circuit.

[0095] The above are only preferred specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed in the present application according to the technical solution and application concept of the present application, which should be covered by the protection scope of the present application.

[0096] Those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A protection circuit, characterized in that: The protection circuit is applied to electronic equipment, and the protection circuit comprises: a power port, a surge protection circuit, a reverse voltage protection circuit and an overvoltage protection circuit; The power port is connected to the surge protection circuit, the surge protection circuit is connected to the first ground line, and the surge protection circuit is used to suppress the transient voltage of the protection circuit; The anti-reverse voltage circuit is connected to the power port and connected in parallel with the anti-surge circuit. The anti-reverse voltage circuit is also connected to the second ground line. The anti-reverse voltage circuit is used to eliminate the negative voltage of the protection circuit. The overvoltage protection circuit is connected to the power port and is connected in parallel with the reverse voltage protection circuit and the overvoltage protection circuit respectively. The overvoltage protection circuit is also connected to the second ground line. The overvoltage protection circuit is used to stop the output voltage when the input voltage of the overvoltage protection circuit is greater than the threshold voltage.

2. The protection circuit according to claim 1, characterized in that: The anti-reverse voltage circuit includes a first resistor, a second resistor, a field effect transistor and a capacitor; A first end of the first resistor is connected to the power port, a second end of the first resistor is connected to a first end of the second resistor, and a second end of the second resistor is connected to a second ground line; The field effect tube is respectively connected to the second end of the first resistor, the second end of the second resistor and the surge protection circuit; The first end of the capacitor is connected to the power port, and the second end of the capacitor is connected to the second ground line.

3. The protection circuit according to claim 2, characterized in that: The field effect transistor is an N-channel field effect transistor, and the N-channel field effect transistor includes a gate, a source and a drain; The gate is connected to the second end of the first resistor, the source is connected to the second end of the second resistor, and the drain is connected to the surge protection circuit.

4. The protection circuit according to claim 2, characterized in that: The first resistance is smaller than the second resistance.

5. The protection circuit according to any one of claims 2 to 4, characterized in that: The component parameters corresponding to the first resistor, the second resistor, the field effect transistor and the capacitor are determined according to the overvoltage protection circuit.

6. The protection circuit according to any one of claims 1 to 4, characterized in that: The surge protection circuit includes a transient suppression diode; The power port is connected to a first end of the transient voltage suppression diode, and a second end of the transient voltage suppression diode is connected to a first ground line.

7. The protection circuit according to claim 6, characterized in that: The diode type of the transient suppression diode is determined according to the installation location of the electronic device, power adapter parameters and rated voltage.

8. The protection circuit according to any one of claims 1 to 4, characterized in that: The overvoltage protection circuit includes an overvoltage protection chip; the overvoltage protection chip includes an input terminal, an output terminal and a plurality of ground terminals; The input end of the overvoltage protection chip is connected to the power port, the output end of the overvoltage protection chip is connected to the subsequent circuit of the electronic device, and the multiple grounding ends are connected to the second ground wire.

9. The protection circuit according to claim 8, characterized in that: The chip type of the overvoltage protection chip is determined according to the surge protection circuit and the rated voltage of the electronic device.

10. An electronic device, characterized in that: The electronic device comprises the protection circuit according to any one of claims 1-9.

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