CN110071494A - A kind of protection circuit and electronic equipment - Google Patents

Abstract

The embodiment of the invention discloses a protection circuit and an electronic device. The protection circuit includes: a first power supply terminal and a second power supply terminal; a first protection unit and a second protection unit, a first terminal of the first protection unit is electrically connected to the first power supply terminal, and the first protection unit is electrically connected to the first power supply terminal. The second end of the unit is electrically connected to the first end of the second protection unit, and the second end of the second protection unit is electrically connected to the second power supply end; the first capacitive unit, the first capacitive unit A capacitive unit is connected in parallel to both ends of the first protection unit; a second capacitive unit is connected in parallel to both ends of the second protection unit. Compared with the prior art, the embodiments of the present invention can meet the requirements of wide voltage range and low residual voltage at the same time, which is beneficial to improve the protection performance of the subsequent circuit.

Description

A protective circuit and electronic equipment

technical field

The embodiments of the present invention relate to the technical field of electronic circuits, and in particular, to a protection circuit and an electronic device.

Background technique

Electronic equipment has been widely used in rail transit, automotive electronics, communications, new energy, security, consumer electronics, industrial electronics, medical electronics and other industries. The quality of its performance is directly related to whether the relevant equipment can work safely and reliably.

In order to ensure that electronic equipment can work safely and reliably, protection circuits are often designed at the power supply ports of electronic equipment to prevent transient overcurrents caused by lightning strikes and surge overcurrents from flowing into the subsequent circuit and avoid the latter circuit being impacted by overvoltage. In the prior art, metal oxide varistors (Metal Oxide Varistor, MOV) are mostly used in protection circuits. When selecting a MOV, if the voltage range of the subsequent circuit is large, it is necessary to select a MOV with a higher withstand voltage to ensure that the MOV does not operate incorrectly under normal operating voltage. However, with the increase of the withstand voltage capability of the MOV, the residual voltage during its operation also increases, and the protection capability of the subsequent circuit decreases. Therefore, the existing protection circuits have conflicts in adapting to the two performances of wide voltage range and low residual voltage, so that the existing protection circuits cannot meet the requirements of wide voltage range and low residual voltage at the same time, and the protection performance of the subsequent circuit is relatively low. Difference.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a protection circuit and electronic equipment, so as to meet the requirements of wide voltage range and low residual voltage at the same time, and improve the protection performance of the subsequent circuit.

In a first aspect, an embodiment of the present invention provides a protection circuit, where the protection circuit includes: a first power supply terminal and a second power supply terminal;

a first protection unit and a second protection unit, the first end of the first protection unit is electrically connected to the first power supply end, and the second end of the first protection unit is electrically connected to the first end of the second protection unit The terminal is electrically connected, and the second terminal of the second protection unit is electrically connected to the second power terminal;

a first capacitive unit, the first capacitive unit is connected in parallel to both ends of the first protection unit;

A second capacitive unit, the second capacitive unit is connected in parallel with both ends of the second protection unit.

Optionally, the first capacitive unit includes a first capacitor, the first end of the first capacitor serves as the first end of the first capacitive unit, and the second end of the first capacitor serves as the first end of the first capacitor the second end of the first capacitive unit;

The second capacitive unit includes a second capacitor, the first end of the second capacitor serves as the first end of the second capacitive unit, and the second end of the second capacitor serves as the second capacitive unit the second end of the unit.

Optionally, the capacitance value of the first capacitive unit matches the junction capacitance of the first protection unit; the capacitance value of the second capacitive unit matches the junction capacitance of the second protection unit.

Optionally, the capacitance value of the first protection unit is C11, the capacitance value of the first capacitive unit is C12, the capacitance value of the second protection unit is C21, and the capacitance value of the second capacitive unit The value is C22; and, C12≥5·C11, C12≥5·C21, C22≥5·C11, C22≥5·C21.

Optionally, the first protection unit includes a first voltage-limiting protection device, a first end of the first voltage-limiting protection device serves as a first end of the first protection unit, and the first voltage-limiting protection device is used as the first end of the first protection unit. The second end of the type protection device serves as the second end of the first protection unit.

Optionally, the first voltage-limiting protection device includes at least one of a metal oxide varistor or a TVS diode.

Optionally, the second protection unit includes a switch-type protection device, the first end of the switch-type protection device is used as the first end of the second protection unit, and the second end of the switch-type protection device is used as the the second end of the second protection unit.

Optionally, the switching protection device includes at least one of a semiconductor discharge tube or a gas discharge tube.

Optionally, the second capacitive unit includes a second voltage-limiting protection device, and a first end of the second voltage-limiting protection device serves as the first end of the second capacitive unit, and the second The second end of the voltage-limiting protection device serves as the second end of the second capacitive unit.

In a second aspect, an embodiment of the present invention further provides an electronic device, the electronic device includes a protection circuit and a post-stage circuit as provided in any embodiment of the present invention, wherein a first power input end of the post-stage circuit is connected to the The first power supply terminal of the protection circuit is electrically connected, and the second power supply input terminal of the post-stage circuit is electrically connected to the second power supply terminal of the protection circuit.

In the embodiment of the present invention, the first end of the first protection unit is electrically connected to the first power supply end, the second end of the first protection unit is electrically connected to the first end of the second protection unit, and the second end of the second protection unit is electrically connected to the first end of the second protection unit. The second power supply terminal is electrically connected, that is, the first protection unit and the second protection unit are connected in series, so that both the first protection unit and the second protection unit can be used as pressure-bearing devices for the power supply voltage. The voltage is divided on the protection unit, so the voltages across the first protection unit and the second protection unit are both lower than the power supply voltage. Compared with the prior art, the embodiment of the present invention avoids that the protection device withstands the power supply voltage alone. For the same voltage level, on the premise that the device itself is not damaged by overvoltage, the embodiment of the present invention can adopt a protection device with a lower withstand voltage level. Therefore, the residual voltage of the protection device in the on state is low, so that the protection circuit can meet the requirements of a wide voltage range and a low residual voltage at the same time, which is beneficial to improve the protection performance of the protection circuit for the subsequent circuit.

And, in the embodiment of the present invention, the first capacitive unit is connected in parallel with the first protection unit, and the second capacitive unit is connected in parallel with the second protection unit. By adjusting the capacitance values of the first capacitive unit and the second capacitive unit, you can The voltage distribution across the first protection unit and the second protection unit is redistributed, so that the voltage distribution across the first protection unit and the second protection unit is more reasonable, and the protection circuit can bear a higher working voltage. In addition, the first capacitive unit and the second capacitive unit provided by the embodiment of the present invention are both energy storage units, which generate less heat and consume less power during use. Therefore, the first capacitive unit and the second capacitive unit are The unit acts as a voltage divider unit, which can make the power consumption of the protection circuit lower.

Description of drawings

1 is a schematic structural diagram of a protection circuit according to an embodiment of the present invention;

2 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention;

3 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention;

4 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention;

5 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present invention.

Embodiments of the present invention provide a protection circuit. The protection circuit can be applied to the AC power port or the DC power port. FIG. 1 is a schematic structural diagram of a protection circuit according to an embodiment of the present invention. Referring to FIG. 1 , the protection circuit 100 includes: a first power terminal 110 , a second power terminal 120 , a first protection unit 131 , a second protection unit 132 , a first capacitive unit 141 and a second capacitive unit 142 . The first end of the first protection unit 131 is electrically connected to the first power supply end 110 , the second end of the first protection unit 131 is electrically connected to the first end of the second protection unit 132 , and the second end of the second protection unit 132 is electrically connected to the first end of the second protection unit 132 . The second power terminal 120 is electrically connected. The first capacitive unit 141 is connected to both ends of the first protection unit 131 in parallel, and the second capacitive unit 142 is connected to both ends of the second protection unit 132 in parallel.

The first power supply terminal 110 may be electrically connected to the first power supply input terminal 201 of the post-stage circuit 200, and the first power supply input terminal 201 of the post-stage circuit 200 is connected to a first power line (for example, the live wire L of the AC power supply, or The positive pole of the DC power supply); the second power supply terminal 120 can be electrically connected to the second power supply input terminal 202 of the post-stage circuit 200, and the second power supply input terminal 202 of the post-stage circuit 200 is connected to the second power line (for example, the AC power supply Neutral line N, or the negative pole of the DC power supply); that is, the protection circuit 100 can be connected in parallel with the post-stage circuit 200 to realize lightning strike, surge and overcurrent protection for the post-stage circuit 200 .

The first protection unit 131 and the second protection unit 132 refer to circuits or devices with lightning strike and surge protection performance. The device with lightning strike and surge protection performance can be, for example, a semiconductor discharge tube (Thyristor SurgeSuppresser, TSS), a metal oxide varistor (Metal Oxide Varistor, MOV), a gas discharge tube (GasDischarge Tube, GDT) or a TVS diode (Transient Voltage Suppressor, TVS).

The first end of the first protection unit 131 is electrically connected to the first power supply end 110 , the second end of the first protection unit 131 is electrically connected to the first end of the second protection unit 132 , and the second end of the second protection unit 132 is electrically connected to the first end of the second protection unit 132 . The second power supply terminal 120 is electrically connected, that is, the first protection unit 131 and the second protection unit 132 are connected in series, and the power supply voltage is divided on the first protection unit 131 and the second protection unit 132, so that the first protection unit 131 and the second protection unit 132 are divided The voltage across the protection unit 132 is lower than the power supply voltage. In a normal working state, the voltage distribution across the first protection unit 131 and the second protection unit 132 is mainly determined by the internal junction capacitances of the first protection unit 131 and the second protection unit 132 . Due to differences in the types, models or manufacturing processes of the protection devices, the junction capacitances of the protection devices in the first protection unit 131 and the second protection unit 132 may be different. If the junction capacitances of the first protection unit 131 and the second protection unit 132 are different, according to the principle of capacitor series connection, most of the voltage will be distributed to the protection unit with the smaller junction capacitance, resulting in the distributed voltage of the protection unit with the smaller junction capacitance. If it is too high, that is, the voltage division between the first protection unit 131 and the second protection unit 132 is uneven.

The first capacitive unit 141 and the second capacitive unit 142 refer to circuits or devices having capacitive properties. In this embodiment of the present invention, the capacitance value of the first capacitive unit 141 may be set to match the junction capacitance of the first protection unit 131 ; the capacitance value of the second capacitive unit 142 may be set to match the junction capacitance of the second protection unit 132 . Adjusting the capacitance value of the first capacitive unit 141 can change the equivalent capacitance values of the first capacitive unit 141 and the first protection unit 131 ; adjusting the capacitance value of the second capacitive unit 142 can change the second capacitive unit 142 and the equivalent capacitance value of the second protection unit 132 . Therefore, in this embodiment of the present invention, the first capacitive unit 141 and the second capacitive unit 142 are provided, and the voltages across the first protection unit 131 and the second protection unit 132 can be redistributed.

In this embodiment of the present invention, the first protection unit 131 and the second protection unit 132 are connected in series, so that both the first protection unit 131 and the second protection unit 132 can be used as pressure-bearing devices for the power supply voltage. The second protection unit 132 divides the voltage. Therefore, the voltages across the first protection unit 131 and the second protection unit 132 are both lower than the power supply voltage. Compared with the prior art, the embodiment of the present invention avoids that the protection device withstands the power supply voltage alone. For the same voltage level, on the premise that the device itself is not damaged by overvoltage, the embodiment of the present invention can adopt a protection device with a lower withstand voltage level. Therefore, the residual voltage of the protection device in the on state is low, so that the protection circuit 100 can meet the requirements of wide voltage range and low residual voltage at the same time, which is beneficial to improve the protection performance of the protection circuit 100 for the subsequent circuit 200 .

And, in the embodiment of the present invention, the first capacitive unit 141 is connected in parallel with the first protection unit 131, and the second capacitive unit 142 is connected in parallel with the second protection unit 132. By adjusting the first capacitive unit 141 and the second capacitive unit The capacitance value of the unit 142 can redistribute the voltage across the first protection unit 131 and the second protection unit 132, so that the voltage distribution across the first protection unit 131 and the second protection unit 132 is more reasonable, and the protection circuit 100 can bear more high operating voltage. In addition, the first capacitive unit 141 and the second capacitive unit 142 provided by the embodiment of the present invention are both energy storage units, which generate less heat and consume less power during use. Therefore, the first capacitive unit 141 and the second capacitive unit 141 The dual capacitive unit 142 is used as a voltage dividing unit, which can make the power consumption of the protection circuit 100 lower.

FIG. 2 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention. Referring to FIG. 2, on the basis of the foregoing embodiments, optionally, the first capacitive unit includes a first capacitor C1, and the first end of the first capacitor C1 serves as the first end of the first capacitive unit, and the first capacitor The second end of C1 serves as the second end of the first capacitive unit; the second capacitive unit includes a second capacitor C2, the first end of the second capacitor C2 serves as the first end of the second capacitive unit, and the second capacitor C2 The second end of the second capacitive unit is used as the second end of the second capacitive unit.

In the embodiment of the present invention, the first capacitor C1 is connected in parallel with the first protection unit 131, and the second capacitor C2 is connected in parallel with the second protection unit 132. By adjusting the capacitance values of the first capacitor C1 and the second capacitor C2, the first protection The voltages across the unit 131 and the second protection unit 132 are redistributed, so that the voltage distribution across the first protection unit 131 and the second protection unit 132 is more reasonable. In addition, since the first capacitor C1 and the second capacitor C2 are both energy storage units, they will not heat up and consume power during use. Therefore, the first capacitor C1 and the second capacitor C2 are used as voltage dividing units, which can make the protection circuit 100 Low power consumption.

It should be noted that, in the above embodiments, the first capacitive unit and the second capacitive unit are exemplarily shown to include one capacitor, which is not a limitation of the present invention. In other embodiments, the first capacitive unit may also be set. The capacitive unit and the second capacitive unit include two or more capacitors, and the two or more capacitors may be connected in series or in parallel.

FIG. 3 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention. Referring to FIG. 3 , on the basis of the above-mentioned embodiments, optionally, the first protection unit includes a first voltage-limiting protection device MOV1, and the first end of the first voltage-limiting protection device MOV1 serves as the first end of the first protection unit. At one end, the second end of the first voltage-limiting protection device MOV1 serves as the second end of the first protection unit.

The first voltage-limiting protection device MOV1 is also called a clamping-type protection device, and the first voltage-limiting protection device MOV1 may be, for example, a metal oxide varistor or a TVS diode. The metal oxide varistor utilizes the nonlinear characteristics of the varistor. When an overvoltage occurs between the two poles of the metal oxide varistor, the metal oxide varistor can clamp the voltage to a relatively fixed voltage value, thereby Realize the protection of the post-stage circuit. The TVS diode is a high-efficiency protection device in the form of a diode. When the two poles of the TVS diode are impacted by reverse transient high energy, it can quickly change the high impedance between the two poles to low impedance. , so that the voltage between the two poles is clamped at a predetermined value, so as to realize the protection of the subsequent circuit. The first voltage-limiting protection device MOV1 has the characteristics of fast response speed, which is beneficial to improve the corresponding speed of the protection circuit 100 .

Continuing to refer to FIG. 3 , on the basis of the above embodiments, optionally, the second protection unit includes a switch-type protection device TSS1, and the first end of the switch-type protection device TSS1 serves as the first end of the second protection unit, and the switch-type protection device TSS1 The second end of the protection device TSS1 serves as the second end of the second protection unit.

The switching protection device TSS1 may be, for example, a semiconductor discharge tube or a gas discharge tube. The semiconductor discharge tube is made of the thyristor principle. It relies on the breakdown current of the PN junction to trigger the conduction and discharge of the device, and can flow a large surge current or pulse current. The range of its breakdown voltage constitutes the range of overvoltage protection. . When the applied voltage of the gas discharge tube increases to the point where the field strength between the electrodes exceeds the dielectric strength of the gas, the gap between the two poles will break down the discharge, and the original insulating state will be transformed into a conductive state. The voltage of the discharge arc is maintained at the residual voltage level determined by the discharge arc, and the residual voltage is generally very low, so as to realize the protection of the subsequent circuit. The switching protection device TSS1 and the first voltage limiting protection device MOV1 are connected in series, and the power supply voltage is divided by the switching protection device TSS1 and the first voltage limiting protection device MOV1, so that the voltage across the first voltage limiting protection device MOV1 are both lower than the power supply voltage, reducing the residual voltage of the first voltage-limiting protection device MOV1. And, since the residual voltage of the switching protection device TSS1 is lower than that of the first voltage limiting protection device MOV1, setting the switching protection device TSS1 and the first voltage limiting protection device MOV1 in series is further beneficial to reduce the voltage of the protection circuit 100. residual pressure.

On the basis of the above embodiments, compared with the junction capacitance of the first voltage-limiting protection device MOV1, the junction capacitance of the switching protection device TSS1 is generally smaller, and the second protection unit 142 with a larger capacitance value can be connected in parallel. Therefore, the difference between the equivalent capacitance values of the switching protection device TSS1 and the second protection unit 142 is smaller than that of the first protection unit. The second protection unit 142 may be configured as a capacitor, may be configured as a series-parallel connection of multiple capacitors, or may be configured as other capacitive devices in other embodiments, and may be configured as required in practical applications.

FIG. 4 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention. Referring to FIG. 4 , on the basis of the foregoing embodiments, optionally, the second capacitive unit includes a second voltage-limiting protection device MOV2, and the first end of the second voltage-limiting protection device MOV2 serves as the second capacitive unit The first end of the second voltage-limiting protection device MOV2 is used as the second end of the second capacitive unit. Because the junction capacitance of the second voltage-limiting protection device MOV2 is relatively large, in the embodiment of the present invention, the second voltage-limiting protection device MOV2 is connected in parallel with the switch-type protection device TSS1, so that the first voltage-limiting protection device MOV1 and the switch-type protection device MOV1 can be connected in parallel. The voltages across the protection device TSS1 are redistributed, so that the voltage distribution across the first voltage limiting protection device MOV1 and the switching protection device TSS1 is more reasonable, and the protection circuit 100 can bear a higher working voltage.

FIG. 5 is a schematic structural diagram of another protection circuit provided by an embodiment of the present invention. On the basis of the foregoing embodiments, the embodiments of the present invention provide a specific protection circuit. Referring to FIG. 5 , optionally, the protection circuit 100 includes a first power supply terminal 110 , a second power supply terminal 120 , a first voltage limiting protection device MOV1 , a switching protection device TSS1 , a first capacitor C1 and a second capacitor C2 . The first end of the first voltage limiting protection device MOV1 is electrically connected to the first power supply end 110, the second end of the first voltage limiting protection device MOV1 is electrically connected to the first end of the switching protection device TSS1, and the switching protection device The second terminal of TSS1 is electrically connected to the second power terminal 120 . The first capacitor C1 is connected in parallel with both ends of the first voltage limiting protection device MOV1, and the second capacitor C2 is connected in parallel with both ends of the switching protection device TSS1.

Wherein, for example, the first voltage limiting protection device MOV1 is a metal oxide varistor, and the switching protection device TSS1 is a semiconductor discharge tube. In this embodiment of the present invention, by adjusting the capacitance values of the first capacitor C1 and the second capacitor C2, the voltages across the first voltage-limiting protection device MOV1 and the switching protection device TSS1 can be redistributed reasonably, so that the protection circuit 100 can undertake more high operating voltage.

On the basis of the foregoing embodiments, optionally, the capacitance value of the first protection unit 131 is C11, the capacitance value of the first capacitive unit 141 is C12, the capacitance value of the second protection unit 132 is C21, and the second capacitance value is C21. The capacitance value of the sex unit 142 is C22; and, C12≥5·C11, C12≥5·C21, C22≥5·C11, C22≥5·C21.

The junction capacitance of the protection devices in the first protection unit 131 and the second protection unit 132 is an unstable parameter, and there is a problem that the voltage distribution ratio is unstable in different protection circuits 100 . In the embodiment of the present invention, C12≥5·C11, C12≥5·C21, C22≥5·C11, C22≥5·C21, or C12≥10·C11, C12≥10·C21, C22≥10·C11, C22 ≥10·C21, or set C12≥50·C11, C12≥50·C21, C22≥50·C11, C22≥50·C21, that is, set the capacitance value of the first capacitive unit 141 to be much larger than that of the first protection unit 131. Capacitance value, the capacitance value of the first capacitive unit 141 is much larger than the capacitance value of the second protection unit 132, the capacitance value of the second capacitive unit 142 is much larger than the capacitance value of the first protection unit 131, the capacitance value of the second capacitive unit 142 The capacitance value is much larger than that of the second protection unit 132 .

The embodiments of the present invention are set in such a way that the voltage distribution ratio of the first protection unit 131 and the second protection unit 132 is mainly determined by the first capacitive unit 141 and the second capacitive unit 142, and is affected by the first protection unit 131 and the second capacitive unit 142. The influence of the junction capacitance of the protection device in the protection unit 132 is small, which is beneficial to improve the stability of the operation of the protection circuit 100 .

The embodiment of the present invention also provides an electronic device. FIG. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present invention. Referring to FIG. 6 , the electronic device includes the protection circuit provided in any embodiment of the present invention and a back-stage circuit, the first power input terminal of the back-stage circuit is electrically connected to the first power supply terminal of the protection circuit, and the second power supply terminal of the back-stage circuit is electrically connected. The power input terminal is electrically connected to the second power terminal of the protection circuit. Exemplarily, the electronic device may be an electronic chip in devices such as automotive electronics, communications, new energy, security, consumer electronics, industrial electronics, and medical electronics.

The electronic device provided by the embodiment of the present invention includes the protection circuit provided by any embodiment of the present invention. Therefore, the electronic device provided by the embodiment of the present invention also has the beneficial effects described in any embodiment of the present invention.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope is determined by the scope of the appended claims.

Claims (10)

1. A protection circuit, characterized in that, comprising: a first power supply terminal and a second power supply terminal; a first protection unit and a second protection unit, the first end of the first protection unit is electrically connected to the first power supply end, and the second end of the first protection unit is electrically connected to the first end of the second protection unit The terminal is electrically connected, and the second terminal of the second protection unit is electrically connected to the second power terminal; a first capacitive unit, the first capacitive unit is connected in parallel to both ends of the first protection unit; A second capacitive unit, the second capacitive unit is connected in parallel with both ends of the second protection unit. 2 . The protection circuit according to claim 1 , wherein the first capacitive unit comprises a first capacitor, and the first end of the first capacitor serves as the first end of the first capacitive unit, 2 . The second end of the first capacitor serves as the second end of the first capacitive unit; The second capacitive unit includes a second capacitor, the first end of the second capacitor serves as the first end of the second capacitive unit, and the second end of the second capacitor serves as the second capacitive unit the second end of the unit. 3 . The protection circuit according to claim 1 , wherein a capacitance value of the first capacitive unit matches a junction capacitance of the first protection unit; and a capacitance value of the second capacitive unit matches the The junction capacitance of the second protection unit. 4 . The protection circuit according to claim 3 , wherein the capacitance value of the first protection unit is C11, the capacitance value of the first capacitive unit is C12, and the capacitance value of the second protection unit is C12. 5 . is C21, and the capacitance value of the second capacitive unit is C22; and, C12≥5·C11, C12≥5·C21, C22≥5·C11, C22≥5·C21. 5 . The protection circuit according to claim 1 , wherein the first protection unit comprises a first voltage-limiting protection device, and a first end of the first voltage-limiting protection device serves as the first protection device 5 . The first end of the unit, and the second end of the first voltage-limiting protection device serves as the second end of the first protection unit. 6 . The protection circuit according to claim 5 , wherein the first voltage-limiting protection device comprises at least one of a metal oxide varistor or a TVS diode. 7 . 7 . The protection circuit according to claim 5 , wherein the second protection unit comprises a switch-type protection device, and the first end of the switch-type protection device serves as the first end of the second protection unit, 8 . The second end of the switch-type protection device serves as the second end of the second protection unit. 8 . The protection circuit according to claim 7 , wherein the switching protection device comprises at least one of a semiconductor discharge tube or a gas discharge tube. 9 . 9 . The protection circuit according to claim 7 , wherein the second capacitive unit comprises a second voltage-limiting protection device, and a first end of the second voltage-limiting protection device serves as the second voltage-limiting protection device. 10 . The first end of the capacitive unit, and the second end of the second voltage-limiting protection device serves as the second end of the second capacitive unit. 10. An electronic device, characterized in that the electronic device comprises the protection circuit according to any one of claims 1-9 and a subsequent stage circuit, wherein the first power input end of the subsequent stage circuit is connected to the protection circuit. The first power supply terminal of the circuit is electrically connected, and the second power supply input terminal of the post-stage circuit is electrically connected to the second power supply terminal of the protection circuit.