CN218897166U

CN218897166U - DC power supply surge protection circuit

Info

Publication number: CN218897166U
Application number: CN202222597791.3U
Authority: CN
Inventors: 梁浩; 于文尧; 袁尧
Original assignee: Huaian Zhongke Jingshang Intelligent Network Research Institute Co ltd
Current assignee: Huaian Zhongke Jingshang Intelligent Network Research Institute Co ltd
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2023-04-21
Anticipated expiration: 2032-09-29

Abstract

A surge protection circuit of a direct current power supply adopts a low-cost design scheme at the input end of a power supply chip, a surge absorption circuit is skillfully designed through a voltage stabilizing tube, a diode, a triode, a resistor, a capacitor and the like, when a power supply voltage has a surge pulse signal higher than a certain value, the protection circuit starts to work and absorbs a high-voltage pulse signal, and when the high-voltage part is released and returns to a normal voltage, the protection circuit stops working, so that the working stability of the power supply of the whole product is not influenced. The protection circuit design is used in an electronic product system, so that the stability of the voltage of the input end of the power chip can be effectively protected, the cost is low, the practicability is high, and the use stability of the product is improved.

Description

DC power supply surge protection circuit

Technical Field

The disclosure relates to the technical field of power supply chips, and in particular relates to a direct-current power supply surge protection circuit.

Background

The integrated direct current power supply chip is widely applied to electronic products at present, and the design cost and the production cost of the electronic products are greatly reduced mainly due to small volume, simple chip peripheral equipment and wider applicable voltage range. Because the power supply chip has a complex use scene in the electronic product, particularly in a circuit environment with larger power supply surge current, the voltage is easy to instantly float, and the power supply chip and peripheral devices of the power supply chip are damaged or directly damaged, so that the service life of the electronic product is seriously influenced.

Disclosure of Invention

In view of the above problems, the present disclosure provides a low-cost, dc power supply surge protection circuit that can provide a stable and reliable power supply input voltage.

The present disclosure provides a dc power supply surge protection circuit, comprising:

the filter capacitor is connected with the power input end, and the other end of the filter capacitor is grounded;

meanwhile, the power input end is connected into the base electrode of the triode Q1 through a reverse isolation diode D1, a current-limiting resistor R2, a voltage-stabilizing tube D4 and a current-limiting resistor R3 which are sequentially connected in series, wherein the negative electrode of the voltage-stabilizing tube D4 is connected with R2, and the positive electrode is connected with R3; the emitter of the triode Q1 is grounded; the collector of the Q1 is connected with the cathode of the diode D1 through a divider resistor R1; the power input end of the resistor R3 is grounded through a voltage clamping diode and a charge-discharge capacitor C5 which are connected in parallel;

meanwhile, the cathode of the diode D1 is connected with the emitter of the triode Q7, the collector of the triode Q1 is connected with the base of the Q7 through the current limiting resistor R4, the collector of the Q7 is connected with the cathode of the TVS tube D3, the anode of the TVS tube D3 is grounded through the protection resistor R6,

meanwhile, the cathode of the diode D1 is connected with the power supply output end through the filter inductor L1;

wherein the reverse withstand voltage of D3 is lower than the input power supply voltage.

Further, the filter capacitor comprises capacitors C1, C2, C3 and C4, wherein the capacitors C1 and C2 are connected with the power input end, the other end of the capacitor C1 is connected with the capacitor C3, the other end of the capacitor C2 is connected with the capacitor C4, and the other ends of the capacitor C3 and the capacitor C4 are grounded.

Further, the voltage clamping diodes are voltage clamping diodes D2 and D6 which are sequentially connected in series.

Further, the D2 and D3 diodes are fast recovery diodes.

Further, the cathode of the diode D1 is connected to the base electrode of the triode Q7 through a charge-discharge capacitor C6 and a divider resistor R5 which are connected in parallel; meanwhile, the cathode of the diode D1 is grounded via the filter capacitor C7.

When surge spike pulse exceeding the power supply voltage is input into the external power supply, the protection circuit starts to work, the first-stage triode Q1 is turned on, the base electrode of the triode Q7 is pulled down to conduct Q7, after the Q7 is conducted, the surge pulse is absorbed through the TVS diode D3 and the protection resistor R6, and then stable power supply voltage is output through the filter inductor L1.

Compared with the prior art, the beneficial effects of the present disclosure are: (1) When the power supply voltage has a surge pulse signal higher than a certain value, the protection circuit starts to work, absorbs the high-voltage pulse signal, and stops working when the high-voltage part is released and returns to the normal voltage, so that the working stability of the whole product power supply is not influenced; (2) When the protection circuit is used in an electronic product system, the stability of the voltage of the input end of the power chip can be effectively protected, and the service life of the product is greatly prolonged; and (3) the cost is low, and the practicability is high.

Drawings

The foregoing and other objects, features and advantages of the disclosure will be apparent from the following more particular descriptions of exemplary embodiments of the disclosure as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the disclosure.

Fig. 1 shows a schematic circuit configuration diagram according to an exemplary embodiment of the present disclosure.

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present disclosure are illustrated in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

An exemplary embodiment of a protection circuit provided in the present disclosure is shown in fig. 1, and includes:

the filter comprises a first part of filter capacitors C1, C2, C3 and C4, a second part of reverse isolation diode D1, a third part of current-limiting resistor R2, a voltage stabilizing tube D4, a filter capacitor C7, a charge-discharge capacitor C5, voltage clamping diodes D2 and D6, a current-limiting resistor R3, a triode Q1, a fourth part of pull-up voltage dividing resistor R1, a current-limiting resistor R4, a charge-discharge capacitor C6, a bias resistor R5, a triode Q7, a TVS tube D3, a protection resistor R6 and a fifth part of filter inductor L1.

When an external power supply VCC is connected in, the anode of a diode D1 is connected with four capacitors C1 and C2, the other end of the diode D1 is connected with a capacitor C3 and the other end of the capacitor C2 is connected with four capacitors C4, the other end of the capacitor C3 and the other end of the capacitor C4 are grounded, the cathode of the diode D1 is connected with one end of a resistor R2, a capacitor C7, a resistor R1, a capacitor C6, a resistor R5, an emitter of a triode Q7 and an inductor L1, a voltage stabilizing tube D4 is connected at the lower end of the current limiting resistor R2, the capacitor C5, the diode D2 and the current limiting resistor R3 are connected with the anode of the voltage stabilizing tube D4, the other end of the capacitor C5 is grounded, the other end of the resistor R3 is connected with a base of a triode Q1, the cathode of the diode D2 is connected with the anode of a diode D6, the cathode of the diode D6 is grounded, the emitter of the triode Q1 is connected with one end of the resistor R4, the other end of the capacitor C7 is grounded, the other ends of the resistors R4 and R5, the other ends of the capacitor C6 are connected with the emitter of the resistor Q7, the collector of the triode Q7 is connected with the cathode of the TVS 3, the other end of the resistor R3 is connected with the other end of the resistor R6, and the other end of the resistor R6 can be grounded, and the voltage of the other resistor L can be connected with the resistor L1.

Wherein, the D3 reverse withstand voltage is lower than the input voltage VCC, and the D2 and D6 diodes preferably adopt fast recovery diodes.

When surge spike pulse exceeding the power supply voltage is input into the external power supply, the protection circuit starts to work, the first-stage triode Q1 is turned on, the base electrode of the triode Q7 is pulled down to conduct Q7, after the Q7 is conducted, the surge pulse is absorbed through the TVS diode D3 and the protection resistor R6, and stable power supply voltage is output through the filter inductor L1.

Application example:

the input voltage VCC adopts direct current 80V input, the highest input voltage is 90V, the D4 adopts an 85V voltage stabilizing tube, the TVS tube D3 adopts reverse 40V withstand voltage, and other devices adopt electronic components with proper parameters. When the external input voltage is smaller than 85V, the voltage stabilizer D4 is in a cut-off state, the triode Q1 and Q7 are kept in a cut-off state, when the input voltage has a pulse signal larger than 86.4V, the capacitors C1, C2, C3 and C4 play a role in filtering, the voltage stabilizer D4 works, a voltage larger than 1.4V is output to one end of the anode of the diode D2 and one end of the current limiting resistor R3, the anode voltage of the diode D2 is not larger than 1.4V due to the fact that the cathode of the diode D6 is grounded, the triode Q1 is stably conducted, the base voltage of the triode Q7 is instantly pulled down after the triode Q1 is conducted, so that the triode Q7 is conducted, the pulse voltage is added to the upper side of the TVS tube D3 after the triode Q7 is conducted, the high-voltage pulse is instantly conducted due to the fact that the reverse voltage-withstanding selection of the D3 is lower than the input voltage VCC, the high-voltage pulse is released to the high-voltage part through the protection resistor R6, the input end voltage is smaller than 85V after the high-voltage is released, the triode D4 does not work, and the triode Q1 and the triode Q7 is in a cut-off state.

Therefore, when the power supply voltage has a surge pulse signal higher than a certain value, the protection circuit starts to work, absorbs the high-voltage pulse signal, and when the high-voltage part is released and returns to the normal voltage, the protection circuit stops working, so that the working stability of the whole product power supply is not affected.

When the protection circuit is used in an electronic product system, the stability of the voltage of the input end of the power chip can be effectively protected, the cost is low, the practicability is high, and the use stability of the product is improved.

The foregoing technical solutions are merely exemplary embodiments of the present utility model, and various types of modifications or variations can be easily made by those skilled in the art based on the application methods and principles disclosed in the present utility model, not limited to the methods described in the foregoing specific embodiments, so that the foregoing description is only preferred and not in a limiting sense.

Claims

1. A dc power supply surge protection circuit, comprising:

2. The protection circuit of claim 1, wherein the filter capacitor comprises capacitors C1, C2, C3, and C4, wherein the capacitors C1 and C2 are connected to the power input terminal, the other end of the capacitor C1 is connected to the capacitor C3, and the other end of the capacitor C2 is connected to the capacitor C4, and the other ends of the capacitor C3 and the capacitor C4 are grounded.

3. The protection circuit of claim 1, wherein the voltage clamping diodes are voltage clamping diodes D2, D6 connected in series.

4. A protection circuit according to claim 3, wherein the D2, D3 diodes are fast recovery diodes.

5. The protection circuit according to any one of claims 1 to 4, wherein the cathode of the diode D1 is connected to the base of the triode Q7 via a charge-discharge capacitor C6 and a voltage dividing resistor R5 connected in parallel; meanwhile, the cathode of the diode D1 is grounded via the filter capacitor C7.