Power supply protection circuit

Automatic power-off protection is achieved by using voltage divider resistors and self-resetting fuses in the power control circuit. This solves the problem of controller damage caused by short circuits or excessive current in intelligent automotive electronic products, realizes automatic circuit protection and functional expansion, and has a simple structure and low cost.

CN223872027UActive Publication Date: 2026-02-03IRIDIUM ELECTRONIC TECH (SHANGHAI) CO LTD
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Patent Information

Application Number
CN202520314954.3
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-02-26
Publication Date
2026-02-03
Estimated Expiration
2035-02-26

AI Technical Summary

Technical Problem

The electronic components of existing smart cars are prone to controller damage when short-circuited or subjected to excessive current, and existing power protection circuits cannot effectively prevent such damage.

Method used

The power control circuit includes resistors, NPN transistors, PMOS transistors, resettable fuses, and capacitors. Automatic power-off protection is achieved through voltage divider sampling and resettable fuses. Signal stability is improved by combining diode clamping circuits and filter capacitors.

Benefits of technology

It automatically cuts off power when electronic products are short-circuited or the current is too high, to avoid damage to the controller, and expands the circuit function through the load power supply interface. It has a simple structure and low cost.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a power supply protection circuit. The power supply protection circuit comprises a power supply control circuit and a first voltage sampling circuit. The power supply control circuit comprises a resistor R38, a resistor R28, a resistor R36, a triode, a PMOS (P-channel Metal Oxide Semiconductor) tube and a resettable fuse F1; the resistor R38 is connected with a driving signal end and a base electrode of the triode; the emitter of the triode is grounded; the collector electrode of the triode is connected with a resistor R36, and the resistor R36 is connected with the grid electrode of the PMOS tube and a resistor R28; the source electrode of the PMOS tube is respectively connected with a + 12V power supply and a resistor R28; the drain electrode of the PMOS tube is connected with the resettable fuse F1; the resettable fuse F1 is connected with a load power supply interface; the first voltage sampling circuit comprises a resistor R17 and a resistor R37; one end of the resistor R37 is grounded, and the other end is respectively connected with the resistor R17 and the base electrode of the triode; and the resistor R17 is respectively connected with the resettable fuse F1 and the load power supply interface. According to the utility model, automatic power-off can be realized when an electronic product carried on an automobile is short-circuited or the current is too large, so that the controller is prevented from being damaged.
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Description

TECHNICAL FIELD

[0001] The utility model relates to intelligent automobile technical field especially, relate to a power protection circuit. BACKGROUND

[0002] With the popularization rate of intelligent automobile in society is higher and higher, the electronic product carried on intelligent automobile is also more and more.This kind of carried electronic product is powered by the controller of intelligent automobile.Most of the time when this kind of electronic product short-circuit or current is too large and other abnormal conditions, will cause the controller damage and cause big economic loss.Therefore, how to send a new structure's power protection circuit to overcome the above problems in the prior art, is the direction that the person skilled in the art needs to further study. CONTENT OF THE UTILITY MODEL

[0003] The utility model discloses a power protection circuit, can realize automatic power-off when the electronic product carried on intelligent automobile short-circuit or current is too large and other abnormal conditions, avoid the controller damage.

[0004] The utility model discloses a power protection circuit, it includes:

[0005] Power control circuit, the power control circuit includes: resistance R38, resistance R28, resistance R36, NPN triode Q6, PMOS tube Q5 and self recovery fuse F1, one end of resistance R38 is connected drive signal end DRIVER, the other end of resistance R38 is connected the base of NPN triode Q6, the emitter of NPN triode Q6 is grounded, the collector of NPN triode Q6 is connected one end of resistance R36, the other end of resistance R36 is connected the gate of PMOS tube Q5 and one end of resistance R28 respectively, the source of PMOS tube Q5 is connected +12V power supply and the other end of resistance R28 respectively, the drain of PMOS tube Q5 is connected one end of self recovery fuse F1, the other end of self recovery fuse F1 is connected load power supply interface SEN_POW,

[0006] First voltage sampling circuit, the first voltage sampling circuit includes: resistance R17 and resistance R37, one end of resistance R37 is grounded, the other end of resistance R37 is connected one end of resistance R17 and the base of NPN triode Q6 respectively, the other end of resistance R17 is connected the other end of self recovery fuse F1 and load power supply interface SEN_POW respectively.

[0007] By adopting the technical scheme, when the high voltage is output from the driving signal end DRIVER, the NPN transistor Q6 is turned on, the PMOS transistor Q5 is turned on, and the +12V voltage is connected to the load power supply interface SEN_POW through the self-resetting fuse F1, so that the power supply for the loads is realized. The resistance R17 and the resistance R37 are used as the voltage dividing resistors to realize sampling. When the load is short-circuited, the SEN_POW output voltage is instantaneously pulled down, the voltage dividing voltage of the resistance R17 and the resistance R37 is forced to be pulled down, the NPN transistor Q6 is turned off, and then the PMOS transistor Q5 is also turned off, so that the +12V voltage is automatically cut off, and the SEN_POW port has no voltage, that is, the automatic power-off protection is realized. In addition, when the load current is too large at the rear end or the instantaneous current is too large due to short circuit, the resistance of the self-resetting fuse F1 becomes infinite, that is, the +12V power supply circuit is cut off, and therefore, the self-resetting fuse F1 also has the automatic protection function.

[0008] Preferably, the power supply control circuit further comprises a capacitor C2 and a capacitor C5. One end of the capacitor C2 is grounded, and the other end of the capacitor C2 is connected to the other end of the self-resetting fuse F1. One end of the capacitor C5 is grounded, and the other end of the capacitor C5 is connected to the other end of the self-resetting fuse F1.

[0009] By adopting the technical scheme, the capacitor C2 and the capacitor C5 are used to realize filtering, and the stability of the signal output to the load power supply interface SEN_POW is improved.

[0010] Preferably, the resistance R38 has a resistance of 680Ω, the resistance R36 has a resistance of 4.7KΩ, the resistance R28 has a resistance of 47KΩ, the resistance R17 has a resistance of 24kΩ, the resistance R37 has a resistance of 3.3kΩ, the capacitor C2 has a capacitance of 103μF, and the capacitor C5 has a capacitance of 10nF.

[0011] More preferably, the power supply control circuit further comprises a second sampling circuit, and the second sampling circuit comprises a resistance R165, a resistance R167, a capacitor C106, a diode D12A and a diode D12B. One end of the resistance R165 is connected to one end of the resistance R17, and the other end of the resistance R165 is connected to the load power supply interface SEN_POW_DET. One end of the capacitor C106 is connected to the other end of the resistance R165, and the other end of the capacitor C106 is grounded. One end of the resistance R167 is connected to the other end of the resistance R165, and the other end of the resistance R167 is grounded. The positive electrode of the diode D12A is connected to the other end of the resistance R165, and the negative electrode of the diode D12A is connected to the +5V voltage. The positive electrode of the diode D12B is grounded, and the negative electrode of the diode D12B is connected to the other end of the resistance R165.

[0012] By employing this technical solution, resistors R165 and R167 are used as voltage divider resistors to achieve sampling, and are connected to the MCU through the load power supply interface SEN_POW_DET, thereby realizing the functional expansion of the circuit. Diodes D12A and D12B together form a clamping circuit to prevent excessive voltage from damaging the MCU, and capacitor C106 performs filtering to improve the stability of the signal output to the load power supply interface SEN_POW_DET.

[0013] Preferably, the resistance of resistor R165 is 100kΩ; the resistance of resistor R167 is 22kΩ; the capacitance of capacitor C106 is 0.1μF; and diodes D12A and D12B are both BAV99.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] First, this invention can automatically cut off power when electronic products installed in smart cars experience abnormal situations such as short circuits or excessive current, thus preventing damage to the controller.

[0016] Secondly, this invention can connect to an MCU via the load power supply interface SEN_POW_DET, enabling further functional expansion of the circuit.

[0017] Finally, this invention has a simple structure, low manufacturing cost, and is easy to prepare and use. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of Example 1. Detailed Implementation

[0019] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0020] Example 1, please refer to Figure 1 :

[0021] A power protection circuit includes: a power control circuit, a first voltage sampling circuit, and a second sampling circuit.

[0022] The power control circuit includes: resistors R38, R28, and R36; NPN transistor Q6; PMOS transistor Q5; resettable fuse F1; capacitors C2 and C5. One end of resistor R38 is connected to the drive signal terminal DRIVER, and the other end of resistor R38 is connected to the base of NPN transistor Q6; the emitter of NPN transistor Q6 is grounded; the collector of NPN transistor Q6 is connected to one end of resistor R36, and the other end of resistor R36 is connected to the gate of PMOS transistor Q5 and one end of resistor R28; the source of PMOS transistor Q5 is connected to the +12V power supply and the other end of resistor R28; the drain of PMOS transistor Q5 is connected to one end of resettable fuse F1; the other end of resettable fuse F1 is connected to the load power supply interface SEN_POW; one end of capacitor C2 is grounded, and the other end of capacitor C2 is connected to the other end of resettable fuse F1; one end of capacitor C5 is grounded, and the other end of capacitor C5 is connected to the other end of resettable fuse F1.

[0023] The first voltage sampling circuit includes: resistor R17 and resistor R37; one end of resistor R37 is grounded, and the other end of resistor R37 is connected to one end of resistor R17 and the base of NPN transistor Q6 respectively; the other end of resistor R17 is connected to the other end of resettable fuse F1 and the load power supply interface SEN_POW respectively.

[0024] The second sampling circuit includes: resistor R165, resistor R167, capacitor C106, diode D12A, and diode D12B; one end of resistor R165 is connected to one end of resistor R17, and the other end of resistor R165 is connected to the load power supply interface SEN_POW_DET; one end of capacitor C106 is connected to the other end of resistor R165, and the other end of capacitor C106 is grounded; one end of resistor R167 is connected to the other end of resistor R165, and the other end of resistor R167 is grounded; the anode of diode D12A is connected to the other end of resistor R165, and the cathode of diode D12A is connected to a +5V voltage; the anode of diode D12B is grounded, and the cathode of diode D12B is connected to the other end of resistor R165.

[0025] In this example: the resistance of resistor R38 is 680Ω; the resistance of resistor R36 is 4.7KΩ; the resistance of resistor R28 is 47KΩ; the resistance of resistor R17 is 24kΩ; the resistance of resistor R37 is 3.3kΩ; the capacitance of capacitor C2 is 103μF; the capacitance of capacitor C5 is 10nF. The resistance of resistor R165 is 100kΩ; the resistance of resistor R167 is 22kΩ; the capacitance of capacitor C106 is 0.1μF; diodes D12A and D12B are both BAV99.

[0026] In practice, its working process is as follows:

[0027] When the DRIVER outputs a high voltage, NPN transistor Q6 and PMOS transistor Q5 are turned on. The +12V voltage is connected to the load power supply interface SEN_POW via the resettable fuse F1, thus powering the loads. Resistors R17 and R37 act as voltage divider resistors for sampling. When the load is short-circuited, the SEN_POW output voltage is momentarily pulled low. At this time, the voltage divided by resistors R17 and R37 is forcibly pulled low, turning off NPN transistor Q6, and subsequently PMOS transistor Q5, automatically cutting off the +12V voltage and leaving the SEN_POW port without voltage, thus achieving automatic power-off protection. Furthermore, when the downstream load current is too large, or when the instantaneous current caused by a short circuit is too large, the resistance of the resettable fuse F1 becomes infinite, effectively cutting off the +12V power supply circuit. Therefore, the resettable fuse F1 also provides automatic protection. Resistors R165 and R167 serve as voltage divider resistors for sampling and are connected to the MCU via the load power supply interface SEN_POW_DET, thus expanding the circuit's functionality. Diodes D12A and D12B together form a clamping circuit to prevent excessive voltage from damaging the MCU, and capacitor C106 performs filtering, improving the stability of the signal output to the load power supply interface SEN_POW_DET.

[0028] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings. However, this utility model is not limited to the above embodiments. Even if various changes are made to this utility model, if these changes fall within the scope of the claims of this utility model and their equivalents, they shall still fall within the protection scope of this utility model.

Claims

1. A power supply protection circuit, characterized in that, include: A power control circuit includes: resistors R38, R28, and R36; an NPN transistor Q6; a PMOS transistor Q5; and a resettable fuse F1. One end of resistor R38 is connected to the drive signal terminal (DRIVER), and the other end of resistor R38 is connected to the base of the NPN transistor Q6. The emitter of the NPN transistor Q6 is grounded. The collector of the NPN transistor Q6 is connected to one end of resistor R36, and the other end of resistor R36 is connected to the gate of the PMOS transistor Q5 and one end of resistor R28. The source of the PMOS transistor Q5 is connected to a +12V power supply and the other end of resistor R28. The drain of the PMOS transistor Q5 is connected to one end of the resettable fuse F1. The other end of the resettable fuse F1 is connected to the load power supply interface SEN_POW. The first voltage sampling circuit includes: resistor R17 and resistor R37; one end of resistor R37 is grounded, and the other end of resistor R37 is connected to one end of resistor R17 and the base of NPN transistor Q6; the other end of resistor R17 is connected to the other end of resettable fuse F1 and the load power supply interface SEN_POW.

2. The power protection circuit according to claim 1, characterized in that, The power control circuit also includes: Capacitor C2, one end of which is grounded, and the other end of which is connected to the other end of the resettable fuse F1; Capacitor C5, one end of which is grounded, and the other end of which is connected to the other end of the resettable fuse F1.

3. The power protection circuit according to claim 2, characterized in that, The resistance of resistor R38 is 680Ω; the resistance of resistor R36 is 4.7KΩ; the resistance of resistor R28 is 47KΩ; the resistance of resistor R17 is 24kΩ; the resistance of resistor R37 is 3.3kΩ; the capacitance of capacitor C2 is 103μF; and the capacitance of capacitor C5 is 10nF.

4. The power protection circuit according to claim 3, characterized in that, Also includes: The second sampling circuit includes: resistor R165, resistor R167, capacitor C106, diode D12A and diode D12B. One end of resistor R165 is connected to one end of resistor R17, and the other end of resistor R165 is connected to the load power supply interface SEN_POW_DET; one end of capacitor C106 is connected to the other end of resistor R165, and the other end of capacitor C106 is grounded; one end of resistor R167 is connected to the other end of resistor R165, and the other end of resistor R167 is grounded; the anode of diode D12A is connected to the other end of resistor R165, and the cathode of diode D12A is connected to a +5V voltage; the anode of diode D12B is grounded, and the cathode of diode D12B is connected to the other end of resistor R165.

5. The power protection circuit according to claim 4, characterized in that, The resistance of resistor R165 is 100kΩ; the resistance of resistor R167 is 22kΩ; the capacitance of capacitor C106 is 0.1μF; and diodes D12A and D12B are both BAV99.