Power supply overvoltage protection circuit

Abstract

The utility model provides a power supply overvoltage protection circuit. Comprising a control network module and a turn-off module, the control network module comprises a voltage stabilizing diode, a first resistor, a second resistor and a PNP triode, one end of the first resistor is connected to a power input end, and the other end of the first resistor is connected with the second resistor and the voltage stabilizing diode; and the turn-off module comprises a field effect transistor, the first resistor and one end of an E electrode of the PNP triode are jointly connected to a source electrode of the field effect transistor, one end of a C electrode of the PNP triode is connected to a grid electrode of the field effect transistor, and the turn-off module is used for performing turn-off control on the field effect transistor to realize an overvoltage protection function. The power supply overvoltage protection circuit provided by the utility model has the advantages of simple structure, quick response, simplicity, high efficiency and low cost.

Description

Technical Field

[0001] The present application relates to the technical field of power supply circuits, and in particular to a power supply overvoltage protection circuit. Background Art

[0002] A power supply overvoltage protection circuit is a common circuit protection device. Its function is to immediately shut down the circuit when the circuit voltage exceeds a set value, protecting the components within the circuit from damage caused by excessive voltage. A power supply overvoltage protection circuit typically consists of an overvoltage protection device and a trigger device.

[0003] Overvoltage protection works by using a voltage detection circuit within the circuit to detect whether the voltage exceeds a set threshold. Once the voltage exceeds the threshold, the overvoltage protection device is triggered, allowing the protection device to protect the circuit. The overvoltage protection threshold is usually set according to the requirements of the circuit design and is generally set above the maximum rated voltage of the circuit.

[0004] The key point of a power supply overvoltage protection circuit is its ability to react very quickly to provide better protection. Therefore, developing a power supply overvoltage protection circuit that reacts quickly and is low-cost is of great significance. Utility Model Content

[0005] In view of the above-mentioned deficiencies in the prior art, the present application provides a power supply overvoltage protection circuit.

[0006] According to one aspect of the present application, a power supply overvoltage protection circuit is provided, comprising: a control network module and a shutdown module, wherein the control network module comprises a voltage-stabilizing diode, a first resistor, a second resistor, and a PNP transistor, wherein one end of the first resistor is connected to a power supply input terminal, and the other end thereof is connected to the second resistor and the voltage-stabilizing diode;

[0007] The shutdown module includes a field effect tube, the first resistor and one end of the E pole of the PNP transistor are commonly connected to the source of the field effect tube, and one end of the C pole of the PNP transistor is connected to the gate of the field effect tube, which is used to shut down the field effect tube Q2 to achieve overvoltage protection function.

[0008] In an optional embodiment of the present application, the circuit further includes: a third resistor, a fourth resistor and a fifth resistor, one end of the third resistor is connected to the S pole of the field effect tube, and the other end thereof is connected to the fourth resistor, one end of the fifth resistor is connected to the D pole of the field effect tube, and the other end thereof is grounded together with the fourth resistor.

[0009] A power supply overvoltage protection circuit provided in an embodiment of the present application includes: a control network module and a shutdown module, the control network module including a voltage-stabilizing diode, a first resistor, a second resistor, and a PNP transistor, one end of the first resistor being connected to a power input terminal, and the other end thereof being connected to the second resistor and the voltage-stabilizing diode; the above-mentioned shutdown module including a field-effect transistor, the above-mentioned first resistor and one end of the E-pole of the PNP transistor being jointly connected to the source of the field-effect transistor, and one end of the C-pole of the PNP transistor being connected to the gate of the field-effect transistor, for shutting off the field-effect transistor Q2, thereby realizing an overvoltage protection function. In this solution, after detecting a circuit overvoltage, the control network module controls the field-effect transistor to operate and shut down, thereby quickly and sensitively realizing overvoltage protection. This solution has the positive effects of being simple, efficient, and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Other features, objects and advantages of the present invention will become more apparent from the detailed description of the non-limiting embodiments with reference to the following drawings:

[0011] Figure 1 The present invention provides a schematic structural diagram of a power supply overvoltage protection circuit according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0012] Overvoltage protection works by using a voltage detection circuit within the circuit to detect whether the voltage exceeds a set threshold. Once the voltage exceeds the threshold, the overvoltage protection device is triggered, allowing the protection device to protect the circuit. The overvoltage protection threshold is usually set according to the requirements of the circuit design and is generally set above the maximum rated voltage of the circuit.

[0013] The key point of the power supply overvoltage protection circuit is that it can react very quickly to provide better protection effect; based on this, the embodiment of the present application provides a power supply overvoltage protection circuit. The following is a detailed description of this solution through specific embodiments.

[0014] Reference Figure 1 In the specific embodiment shown, a power supply overvoltage protection circuit is provided in this embodiment, including: a control network module and a shutdown module, the control network module includes a voltage-stabilizing diode ZD1, a first resistor R1, a second resistor R2 and a PNP transistor Q1, one end of the above-mentioned first resistor R1 is connected to the power input terminal Vin, and the other end thereof is connected to the second resistor R2 and the voltage-stabilizing diode ZD1; the above-mentioned shutdown module includes a field-effect tube Q2, the first resistor R1 and one end of the E pole of the PNP transistor Q1 are commonly connected to the source of the field-effect tube Q2, and one end of the C pole of the PNP transistor Q1 is connected to the gate of the field-effect tube Q2, which is used to shut down the field-effect tube Q2 to achieve an overvoltage protection function.

[0015] In one embodiment of the present application, the above-mentioned circuit also includes: a third resistor R3, a fourth resistor R4 and a fifth resistor R5, one end of the third resistor R3 is connected to the S pole of the field effect transistor Q2, and the other end thereof is connected to the fourth resistor R4, one end of the fifth resistor R5 is connected to the D pole of the field effect transistor Q2, and the other end thereof and the fourth resistor R4 are grounded.

[0016] It includes a voltage-stabilizing diode ZD1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a PNP transistor Q1 and a field-effect transistor Q2; the voltage-stabilizing diode ZD1, the first resistor R1, the second resistor R2 and the PNP transistor Q1 form a control network module, the first resistor R1 of the control network module and one end of the E pole of the PNP transistor Q1 are commonly connected to the source of the field-effect transistor Q2, and the C pole end of the PNP transistor Q1 of the control network is connected to the gate of the field-effect transistor Q2, which is used to control the field-effect transistor Q2 to be turned off and realize the overvoltage protection function.

[0017] Specifically, when the above circuit is working, when the Vin input voltage is within the set range, the voltage regulator diode ZD1 is not broken down and turned on, the connection point between the first resistor R1 and the second resistor R2 is at a high level, the B pole of the PNP transistor Q1 is also at a high level, the EB of the PNP transistor Q1 is not turned on, and the GS of the P-MOS field effect transistor Q2 is normally turned on according to the value set by the third resistor R3.

[0018] When the Vin input voltage is higher than the preset voltage, the Zener diode ZD1 is reversely broken down, the voltage at the connection point between the first resistor R1 and the second resistor R2 is pulled down, the EB voltage of the PNP transistor Q1 exceeds 0.7V, the PNP transistor Q1 is turned on, and the C pole of the PNP transistor Q1 outputs a high level. At this time, the P-MOS field effect transistor Q2 is not turned on, so that Vin to VOUT is cut off and plays the role of overvoltage protection.

[0019] The power supply overvoltage protection circuit provided by the utility model has a simple structure, a quick response, and has the positive effects of being simple, high-efficiency, and low-cost.

[0020] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A power supply overvoltage protection circuit, characterized in that: include: A control network module and a shutdown module, wherein the control network module includes a voltage-stabilizing diode, a first resistor, a second resistor, and a PNP transistor, wherein one end of the first resistor is connected to the power input terminal, and the other end thereof is connected to the second resistor and the voltage-stabilizing diode; The shutdown module includes a field effect tube, the first resistor and one end of the E pole of the PNP transistor are commonly connected to the source of the field effect tube, and one end of the C pole of the PNP transistor is connected to the gate of the field effect tube, which is used to shut down the field effect tube to realize the overvoltage protection function.

2. The circuit according to claim 1, wherein: The circuit also includes: a third resistor, a fourth resistor and a fifth resistor, one end of the third resistor is connected to the S pole of the field effect tube, and the other end thereof is connected to the fourth resistor, one end of the fifth resistor is connected to the D pole of the field effect tube, and the other end thereof is grounded together with the fourth resistor.

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