MOS tube anti-reverse connection and anti-backflow circuit and electronic product
By combining a P-channel MOSFET, a PNP transistor, and a capacitor in a combined circuit structure, the problem of reverse current flow in the MOSFET reverse connection protection method is solved, achieving both reverse connection and reverse current protection effects, improving circuit reliability and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-14
- Publication Date
- 2026-04-07
AI Technical Summary
Existing reverse connection protection methods for MOSFETs have the problem of backflow current, which affects the normal operation of the power supply.
It adopts a combined circuit structure including P-channel MOSFETs, PNP transistors and capacitors. By designing the position of the capacitors and the connection method of the transistors, it achieves the functions of preventing reverse connection and backflow.
It provides reverse connection protection while preventing current backflow, improving the reliability of the protection circuit and reducing the number of components and cost.
Smart Images
Figure CN224097412U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of protection circuit, more specifically, relate to a MOS tube anti-reverse connection anti-backflow circuit and electronic product. BACKGROUND
[0002] Protection circuit is added to electrical equipment, and is used for providing anti-reverse connection anti-backflow protection for electrical equipment, and is a kind of more common circuit type;
[0003] Common anti-reverse circuit has two kinds of diode and MOS tube;One is diode mode, since diode has voltage drop, the voltage drop of diode on market is between 0.3-0.7V currently, certain loss is caused to circuit, and when rear-end load is large, the current flowing through diode is large, and diode heating is relatively large;Another is MOS tube anti-reverse mode, since the internal resistance of MOS tube can be made to mohm level currently, voltage drop is very small, can be ignored, and MOS tube heating is low, so it is a more excellent mode;But the current backflow situation of existing MOS tube mode often exists, and it affects power supply, and a MOS tube anti-reverse connection anti-backflow circuit capable of considering anti-reverse connection and preventing current backflow is required. SUMMARY
[0004] The utility model provides a MOS tube anti-reverse connection anti-backflow circuit, and also provides an electronic product with the MOS tube anti-reverse connection anti-backflow circuit, to solve the above-mentioned defects of prior art.
[0005] The utility model solves the technical scheme that technical problem adopts:
[0006] A MOS tube anti-reverse connection anti-backflow circuit is constructed, including MOS tube assembly and capacitor;In current direction, the capacitor is located downstream of the MOS tube assembly;The MOS tube assembly includes P channel MOS tube, first triode and second triode;The first triode and the second triode are both PNP type triode;The E pole pin and C pole pin of the first triode are connected with the anode and cathode of input respectively, and the B pole pin of the first triode is connected with the B pole pin of the second triode;The E pole pin and C pole pin of the second triode are connected with the anode and cathode of output respectively;The C pole pin of the second triode is grounded;Two ends of the capacitor are connected with the anode and cathode of output respectively;The D pole and S pole of the P channel MOS tube are connected with the E pole pin of the first triode and the E pole pin of the second triode respectively, and the G pole of the P channel MOS tube is connected with the C pole pin of the second triode;The C pole pin of the first triode is connected with the C pole pin of the second triode.
[0007] The utility model discloses a MOS tube anti-reverse connection and anti-backflow circuit, wherein a first resistor is connected in series on a C pole pin of the first triode, a second resistor is connected in series on a C pole pin of the second triode, the other end of the first resistor is connected with the other end of the second resistor, the other end of the second resistor is grounded and connected with the negative pole of the output end, and the other end of the first resistor is connected with the negative pole of the input end.
[0008] An electronic product, wherein the electronic product is provided with the MOS tube anti-reverse connection and anti-backflow circuit as described above.
[0009] The utility model discloses the beneficial effect lies in: the circuit of the application can provide anti-reverse connection protection, prevent current backflow and improve the reliability of the protection circuit. BRIEF DESCRIPTION OF DRAWINGS
[0010] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described below, and the drawings in the following description are only part of the embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor:
[0011] Figure 1 The utility model discloses a MOS tube anti-reverse connection and anti-backflow circuit's circuit diagram. DETAILED DESCRIPTION
[0012] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described below, and the drawings in the following description are only part of the embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor:
[0013] The utility model discloses a MOS tube anti-reverse connection and anti-backflow circuit's circuit diagram. Figure 1As shown, the circuit includes a MOSFET assembly and a capacitor C1; along the current direction, capacitor C1 is located downstream of the MOSFET assembly; the MOSFET assembly includes a P-channel MOSFET Q1, a first transistor Q2, and a second transistor Q3; both the first transistor Q2 and the second transistor Q3 are PNP transistors; the emitter (E) and collector (C) pins of the first transistor Q2 are connected to the positive and negative terminals of the input, respectively, and the base (B) pin of the first transistor Q2 is connected to the base (B) pin of the second transistor Q3; the second transistor Q3... The emitter (E) and collector (C) pins of transistor Q1 are connected to the positive and negative terminals of the output, respectively; the collector (C) pin of the second transistor Q3 is grounded; the two ends of capacitor C1 are connected to the positive and negative terminals of the output, respectively; the drain (D) and source (S) pins of P-channel MOSFET Q1 are connected to the emitter (E) pins of the first transistor Q2 and the second transistor Q3, respectively; the gate (G) pin of P-channel MOSFET Q1 is connected to the collector (C) pin of the second transistor Q3; the collector (C) pin of the first transistor Q2 is connected to the collector (C) pin of the second transistor Q3.
[0014] The circuit described in this application can provide reverse connection protection while preventing current backflow, thus improving the reliability of the protection circuit; the overall circuit structure is simple, involves fewer components, and has low cost.
[0015] Combination Figure 1 The specific circuit principle is as follows:
[0016] Reverse connection protection is achieved by relying on a P-channel MOSFET: When the input voltage supplies power to the load normally, due to the certain internal resistance of the P-channel MOSFET when it is turned on, Vin>Vout, Q2 is turned on, Q3 is turned off, the gate of the P-channel MOSFET is grounded, and the P-channel MOSFET is turned on; when a reverse connection occurs, the P-channel MOSFET is not turned on at this time.
[0017] When the input voltage Vin is disconnected, due to the presence of the output load capacitor C1, Vout>Vin, Q2 is cut off, Q3 is turned on, and the P-channel MOSFET is turned off. At this time, the reverse current cannot pass through the P-channel MOSFET, thus achieving the purpose of preventing reverse current.
[0018] Preferably, a first resistor R1 is connected in series to the collector pin of the first transistor Q2, and a second resistor R2 is connected in series to the collector pin of the second transistor Q3. The other end of the first resistor R1 is connected to the other end of the second resistor R2. The other end of the second resistor R2 is grounded and connected to the negative terminal of the output terminal, and the other end of the first resistor R1 is connected to the negative terminal of the input terminal.
[0019] An electronic product, wherein the electronic product is provided with a MOSFET reverse connection and backflow prevention circuit as described above.
[0020] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A MOSFET reverse connection and reverse current protection circuit, characterized in that, The device includes a MOSFET assembly and a capacitor; the capacitor is located downstream of the MOSFET assembly along the current direction; the MOSFET assembly includes a P-channel MOSFET, a first transistor, and a second transistor; both the first and second transistors are PNP transistors; the emitter (E) and collector (C) pins of the first transistor are connected to the positive and negative terminals of the input terminal, respectively, and the base (B) pin of the first transistor is connected to the base (B) pin of the second transistor; the emitter (E) and collector (C) pins of the second transistor are connected to the positive and negative terminals of the output terminal, respectively; the collector (C) pin of the second transistor is grounded; the two ends of the capacitor are connected to the positive and negative terminals of the output terminal, respectively; the drain (D) and source (S) pins of the P-channel MOSFET are connected to the emitter (E) pins of the first transistor and the second transistor, respectively, and the gate (G) pin of the P-channel MOSFET is connected to the collector (C) pin of the second transistor; the collector (C) pins of the first transistor and the second transistor are connected.
2. The MOS transistor reverse connection and backflow prevention circuit according to claim 1, characterized in that, A first resistor is connected in series to the collector (C) pin of the first transistor, and a second resistor is connected in series to the collector (C) pin of the second transistor. The other ends of the first resistor and the second resistor are connected together. The other end of the second resistor is grounded and connected to the negative terminal of the output. The other end of the first resistor is connected to the negative terminal of the input.
3. An electronic product, characterized in that, The electronic product is provided with a MOS transistor reverse connection and backflow prevention circuit as described in any one of claims 1-2.