Reverse connection prevention circuit, power supply circuit and electronic device

Abstract

The utility model discloses an anti-reverse-connection circuit, a power supply circuit and an electronic device, and the circuit comprises a switching circuit which comprises a first switching tube, the interior of the first switching tube is provided with a body diode, the first end of the first switching tube is coupled with an external power supply, the second end of the first switching tube is coupled with an external load circuit, and the third end of the first switching tube is grounded; when the input voltage input to the first switch tube by the power supply is forward voltage, the body diode is triggered to be conducted, so that the first end and the second end of the first switch tube are conducted, and the input voltage is provided for the load circuit; and when the input voltage is negative voltage, the body diode is triggered to be turned off, and the conductive connection between the power supply and the load circuit is cut off. According to the anti-reverse-connection circuit, the power supply voltage drop can be controlled within a certain range when a large current is applied, so that the load circuit in a low-voltage state can also work normally, and larger working errors of the load circuit are effectively avoided no matter whether the large current is applied or the small current is applied.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and in particular to an anti-reverse connection circuit, a power supply circuit and an electronic device. Background Art

[0002] Nowadays, electronic devices are generally connected to batteries or power supply devices through power cables to obtain working power. If the positive and negative poles of the power input of the electronic device, especially electric vehicles or drones, are reversely connected and a reverse current path is generated, there is an inevitable risk of burning internal devices. Therefore, it is necessary to integrate an anti-reverse connection circuit in each electronic device.

[0003] However, when a large current is input to the reverse connection protection circuit in the prior art, the electronic equipment in the low voltage state usually cannot work normally, and the loss is also large. Most or all of the loss will be converted into heat consumption and affect the performance of the electronic equipment during normal operation. Utility Model Content

[0004] The present application provides an anti-reverse connection circuit, a power supply circuit and an electronic device. The anti-reverse connection circuit can solve the problem in the prior art that when the voltage converter takes into account a wide voltage output, it will cause severe switch tube stress, low module conversion efficiency and limited output power.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide an anti-reverse connection circuit, wherein the anti-reverse connection circuit includes: a switching circuit, including a first switching tube, a body diode is provided inside the first switching tube, the first end of the first switching tube is coupled to an external power supply, the second end of the first switching tube is coupled to an external load circuit, and the third end of the first switching tube is grounded; wherein, when the input voltage input from the power supply to the first switching tube is a positive voltage, the body diode is triggered to turn on to increase the voltage between the first end and the third end of the first switching tube to a first threshold voltage, thereby turning on the first end and the second end of the first switching tube to provide the input voltage to the load circuit; when the input voltage is a negative voltage, the body diode is triggered to turn off to turn off the first end and the second end of the first switching tube, thereby disconnecting the conductive connection between the power supply and the load circuit.

[0006] Among them, the anti-reverse connection circuit also includes a soft start circuit, which is coupled between the second end and the third end of the first switch tube, so that when the voltage between the first end and the third end of the first switch tube is increased to the second threshold voltage, the first end and the second end of the first switch tube are triggered to be turned on; wherein the second threshold voltage is greater than the first threshold voltage.

[0007] The anti-reverse connection circuit further includes a voltage clamping circuit, which is coupled between the second end and the third end of the first switch tube to limit the voltage between the first end and the third end of the first switch tube to a set voltage value.

[0008] Wherein, the voltage clamping circuit includes a first resistor and a Zener diode, the first end of the first resistor is coupled to the third end of the first switch tube, the second end of the first resistor is coupled to the first end of the Zener diode and grounded, and the second end of the Zener diode is coupled to the second end of the first switch tube and the load circuit.

[0009] The anti-reverse connection circuit also includes a filter circuit, which is coupled between the second end of the first switch tube and the load circuit to receive the input voltage sent by the first switch tube, filter the input voltage, and then send it to the load circuit.

[0010] The switch circuit further includes a first capacitor and a second capacitor, wherein the first end of the first capacitor is coupled to the power supply, the first end of the second capacitor and the first end of the first switch tube, the second end of the first capacitor is grounded, and the second end of the second capacitor is grounded.

[0011] Wherein, the anti-reverse connection circuit also includes an isolating switch circuit, which includes a second switch tube and a third switch tube, wherein the first end of the second switch tube is coupled to the second end of the first switch tube, the second end of the second switch tube is coupled to the first end of the load circuit, the third end of the second switch tube is coupled to the first end of the third switch tube, the second end of the third switch tube is grounded, and the third end of the third switch tube is coupled to the second end of the load circuit; wherein, when the second end of the load circuit is at the first level, the third end of the third switch tube triggers the first end and the second end of the third switch tube to be turned on, so as to turn on the first end and the second end of the second switch tube, thereby connecting the second end of the first switch to the first end of the load circuit.

[0012] Wherein, the first switch tube is a P-channel metal oxide semiconductor field effect transistor.

[0013] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a power supply circuit, wherein the power supply circuit includes: a power supply source, an anti-reverse connection circuit and a load circuit, the anti-reverse connection circuit is coupled between the power supply source and the load circuit, and the load circuit is coupled to an external load circuit; wherein the anti-reverse connection circuit is an anti-reverse connection circuit as described in any of the above items.

[0014] To solve the above technical problems, another technical solution adopted in the present application is: to provide an electronic device, wherein the electronic device includes a shell and a functional circuit connected to the shell; wherein the functional circuit is an anti-reverse connection circuit as described in any of the above items, or a power supply circuit as described in any of the above items.

[0015] The beneficial effects of the present application are as follows: Different from the prior art, the switch circuit in the anti-reverse connection circuit provided by the present application includes a first switch tube, a body diode is provided inside the first switch tube, a first end of the first switch tube is coupled to an external power supply, a second end of the first switch tube is coupled to an external load circuit, and a third end of the first switch tube is grounded, so that when the input voltage of the power supply input to the first switch tube is a forward voltage, the body diode can be triggered to conduct, so as to increase the voltage between the first end and the third end of the first switch tube to a first threshold voltage, thereby conducting the first end and the second end of the first switch tube to form a fully conductive path, and providing the input voltage to the load circuit. The circuit is formed by a body diode which is triggered to turn off when the input voltage is a negative voltage, so that the first end and the second end of the first switch tube are in a completely turned-off state and cannot form a conduction path, thereby effectively disconnecting the conductive connection between the power supply and the load circuit, so that when a large current is applied, the power supply voltage drop can be controlled within a certain range, so that the load circuit in a low-voltage state can also work normally; and whether it is a large current or a small current input, a large working error of the load circuit is avoided to ensure good performance; in addition, the power loss of the anti-reverse connection circuit is also small, thereby effectively reducing the risk of device loss or even burning caused by the power loss converted into heat loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0017] Figure 1 It is a structural schematic diagram of a first embodiment of the anti-reverse connection circuit of the present application;

[0018] Figure 2 It is a structural schematic diagram of a second embodiment of the anti-reverse connection circuit of the present application;

[0019] Figure 3 It is a structural schematic diagram of a third embodiment of the anti-reverse connection circuit of the present application;

[0020] Figure 4 It is a structural schematic diagram of an implementation mode of a power supply circuit of the present application;

[0021] Figure 5 It is a structural schematic diagram of an embodiment of the electronic device of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] The terms "first", "second", "third" in this application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the embodiments of this application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0024] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0026] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the first embodiment of the anti-reverse connection circuit of the present application. In this embodiment, the anti-reverse connection circuit 10 includes: a switch circuit 11.

[0027] Among them, a reverse connection prevention circuit 10 provided in the present application is specifically used in electronic devices connected to a battery or other types of power supply 101 through a power connection line, such as electric vehicles or drones, so as to effectively avoid the generation of a reverse current path and burn its internal components when the battery polarity in the electric vehicle or drone is reversely connected to the corresponding circuit. Of course, in other embodiments, the reverse connection prevention circuit 10 can also be specifically used in any other reasonable electronic devices such as industrial control equipment, intelligent robots or photovoltaic energy storage to meet the power demand of the load circuit 102 to avoid reverse current connection, and this embodiment does not limit this.

[0028] Specifically, the switching circuit 11 further includes a first switching tube 111, which has a body diode (not shown) inside. The first end of the first switching tube 111 is coupled to the external power supply 101, the second end of the first switching tube 111 is coupled to the external load circuit 102, and the third end of the first switching tube 111 is grounded.

[0029] It is worth noting that the body diode is an important component of the switch tube. It can be understood as a PN junction between the switch tube substrate and the drain. Its structural characteristics are that the P-type semiconductor switch tube and the N-type semiconductor switch tube are formed in the same material. When a forward voltage is applied, the carriers in the PN junction will be injected into the opposite type of material for recombination, so the current flowing through the device is mainly holes or electrons. Compared with ordinary diodes, the structure of the body diode is more special, so it has the following advantages: the body diode has a high breakdown voltage, and its PN junction has a high withstand voltage characteristic; the body diode has the ability of high-speed switching and fast switching speed; due to the small size of the chip, the reverse recovery time of the body diode is short, which is suitable for high-frequency circuits.

[0030] In addition, the term "coupled" herein refers to any direct and indirect connection means. Therefore, if the first circuit is described as being coupled to the second circuit, it means that the first circuit can be directly connected to the second circuit through electrical connection or signal connection methods such as wireless transmission, optical transmission, etc., or can be indirectly connected to the second circuit through other circuits or connection means.

[0031] Among them, when the input voltage input from the external power supply 101 to the first switch tube 111 is a forward voltage, and the power supply 101 is forwardly connected to the anti-reverse connection circuit 10, the body diode will be triggered to be turned on, so that the voltage at the first end of the first switch tube 111 gradually increases, so that when the voltage between the first end and the third end of the first switch tube 111 is increased to the first threshold voltage, the first end and the second end of the first switch tube 111 are turned on to form a fully conductive path, and the input voltage is provided to the load circuit 102, so that the load circuit 102 can work normally, and effectively avoid the input voltage from generating excessive voltage drop loss when passing through the first switch tube 111, so as to avoid a large working error of the load circuit 102 and ensure good performance; especially in high current applications, the first switch tube 111 can also control the power supply voltage drop within a certain range, so that the load circuit 102 in a low voltage state can also work normally.

[0032] When the input voltage of the power supply 101 to the first switch tube 111 is a negative voltage, that is, when the power supply 101 is reversely connected to the anti-reverse connection circuit 10, the body diode is triggered to turn off, so that the first end and the second end of the first switch tube 111 are in a completely turned-off state, and no conduction path can be formed, thereby effectively disconnecting the conductive connection between the power supply 101 and the load circuit 102, so as to avoid the leakage current from adversely affecting the normal operation of the load circuit 102.

[0033] In the above scheme, when the input voltage input from the power supply 101 to the first switch tube 111 is a positive voltage, the body diode is triggered to conduct, so as to conduct the first end and the second end of the first switch tube 111, thereby forming a fully conductive path, and providing the input voltage to the load circuit 102. When the input voltage is a negative voltage, the body diode is triggered to turn off, so that the first end and the second end of the first switch tube 111 are in a fully turned-off state, and no conductive path can be formed, thereby disconnecting the conductive connection between the power supply 101 and the load circuit 102, so that when a large current is applied, the power supply voltage drop can be controlled within a certain range, so that the load circuit 102 in a low voltage state can also work normally; and whether it is a large current or a small current input, a large working error of the load circuit 102 is avoided to ensure good performance; in addition, the power loss of the anti-reverse connection circuit 10 is also small, thereby effectively reducing the risk of device loss or even burning caused by the conversion of power loss into heat loss.

[0034] In one embodiment, the first switch tube 111 can specifically be a P-channel MOS (Metal Oxide Semiconductor Field Effect Transistor), and the first end of the first switch tube 111 is a source, the second end is a drain, and the third end is a gate, so that when the voltage between the source and the gate of the first switch tube 111 exceeds its own first threshold voltage, it can trigger the source and drain of the first switch tube 111 to turn on, and when it is less than the first threshold voltage, it can trigger the source and drain of the first switch tube 111 to turn off.

[0035] In other embodiments, the first switch tube 111 may be any reasonable P-type semiconductor device such as a P-type thin film transistor or a PNP-type triode, and the present application does not limit this.

[0036] Optionally, the power supply 101 is a battery, or any reasonable power supply device such as a power supply device that converts electric energy from the mains to obtain a constant power supply, and the present application does not limit this.

[0037] Optionally, the load circuit 102 is a voltage detection circuit, a motor drive circuit, a power control circuit, a detection circuit and / or a drive circuit and / or a control circuit, or a power load of any reasonable power load such as a motor or a robotic arm, and this application does not limit this.

[0038] It is understandable that when the load circuit 102 is specifically a detection circuit and / or a drive circuit and / or a control circuit of an electrical load, it is usually necessary to sample the output voltage of the anti-reverse connection circuit 10 in order to effectively reduce the voltage drop of the first switch tube 111 and control the voltage drop within a certain range, so as to effectively avoid excessive sampling errors, thereby achieving better detection and / or drive and / or control functions, and effectively improving the accuracy of detection and / or drive and / or control; and at the same time, it can also effectively avoid loss or even damage to semiconductor devices or chips in the detection circuit and / or drive circuit and / or control circuit; in addition, when the voltage drop of the first switch tube 111 is controlled within a certain range, it can also effectively improve the good and stable operation of the electrical load.

[0039] Optionally, the load circuit 102 can specifically be any reasonable functional circuit with program processing, such as an MCU (Microcontroller Unit) circuit, a single-chip microcomputer or a system-level chip, to serve as a detection circuit and / or a drive circuit and / or a control circuit for the power load, and this application does not limit this.

[0040] See also Figure 2 , Figure 2This is a schematic diagram of the structure of the second embodiment of the anti-reverse connection circuit of the present application. This embodiment is based on the first embodiment of the anti-reverse connection circuit provided in the present application, and the anti-reverse connection circuit 20 further includes a soft start circuit 22 .

[0041] Specifically, the soft start circuit 22 is coupled between the second end and the third end of the first switch tube 211, so that when the input voltage input from the power supply 101 to the first switch tube 211 is a forward voltage, the body diode of the first switch tube 211 is triggered to turn on, and the voltage at the first end of the first switch tube 211 gradually increases, the soft start circuit 22 can utilize the Miller effect in the process of voltage rising between the first end and the third end of the first switch tube 211 to achieve soft start of the output; and specifically, when the voltage between the first end and the third end of the first switch tube 211 is increased to a second threshold voltage, the first end and the second end of the first switch tube 211 are triggered to turn on; wherein the second threshold voltage is greater than the first threshold voltage, so as to effectively prolong the waiting time for triggering the first end and the second end of the first switch tube 211 to be triggered to turn on, thereby achieving the effect of soft start.

[0042] It is worth mentioning that the Miller effect refers to the distributed capacitance or parasitic capacitance between the input and output of the inverting amplifier circuit in electronics. Due to the amplification effect of the amplifier, the capacitance value equivalent to the input end will be expanded by 1+K times, where K is the voltage amplification factor of the amplifier circuit at this stage.

[0043] Optionally, the soft start circuit 22 includes a ceramic capacitor, or a combination circuit consisting of a ceramic capacitor and a set resistor or any other reasonable components, which is not limited in the present application.

[0044] In one embodiment, the anti-reverse connection circuit 20 specifically also includes a voltage clamping circuit 23, which is coupled between the second end and the third end of the first switch tube 211 to limit the voltage between the first end and the third end of the first switch tube 211 to a set voltage value to protect the first switch tube 211 from being damaged due to overvoltage.

[0045] It is understandable that, generally speaking, the maximum voltage of the gate of the switch tube is a fixed value, and is usually ±20 V. Since the first switch tube 211 in the anti-reverse connection circuit 20 is directly connected to the power supply 101, in some extremely bad cases, overvoltage will occur, causing the voltage between the first end and the third end of the first switch tube 211 to exceed the rated voltage value, thereby damaging the first switch tube 211. Therefore, it is necessary to connect a voltage clamping circuit 23 between the second end and the third end of the first switch tube 211 to clamp the voltage of the gate of the first switch tube 211 to protect it from being damaged due to overvoltage.

[0046] Furthermore, in one embodiment, the voltage clamping circuit 23 specifically includes a first resistor (not shown) and a Zener diode (not shown), wherein the first end of the first resistor is coupled to the third end of the first switch tube 211, the second end of the first resistor is coupled to the first end of the Zener diode and is grounded, and the second end of the Zener diode is coupled to the second end of the first switch tube 211 and the load circuit 102, so that when the input voltage input from the power supply 101 to the first switch tube 211 exceeds the rated voltage value, the first resistor and the Zener diode can limit the voltage between the first end and the third end of the first switch tube 211 to a set voltage value, that is, within the rated voltage value, so as to avoid damaging the first switch tube 211.

[0047] In one embodiment, the anti-reverse connection circuit 20 specifically also includes a filter circuit 24, which is coupled between the second end of the first switch tube 211 and the load circuit 102 to receive the input voltage sent by the first switch tube 211, and filter the input voltage before sending it to the load circuit 102 to avoid adverse effects on the normal operation of the load circuit 102.

[0048] In one embodiment, the switch circuit 21 specifically further includes a first capacitor 212 and a second capacitor 213, wherein the first end of the first capacitor 212 is coupled to the power supply 101, the first end of the second capacitor 213 and the first end of the first switch tube 211, the second end of the first capacitor 212 is grounded, and the second end of the second capacitor 213 is grounded, so that the input voltage of the power supply 101 to the first switch tube 211 can be stabilized by using the first capacitor 212 and the second capacitor 213.

[0049] In one embodiment, the anti-reverse connection circuit 20 specifically also includes an isolating switch circuit 25, which includes a second switch tube (not shown in the figure) and a third switch tube (not shown in the figure), the first end of the second switch tube is coupled to the second end of the first switch tube 211, the second end of the second switch tube is coupled to the first end of the load circuit 102, the third end of the second switch tube is coupled to the first end of the third switch tube, the second end of the third switch tube is grounded, and the third end of the third switch tube is coupled to the second end of the load circuit 102.

[0050] Among them, the third end of the third switch tube is at the first level at the second end of the load circuit 102, that is, when the level state provided by the load circuit 102 to the third end of the third switch tube is the first level, it can trigger the first end and the second end of the third switch tube to be turned on, so as to write the zero potential of the second end of the third switch tube into the third end of the second switch tube, so as to trigger the first end and the second end of the second switch tube to be turned on, so that the second end of the first switch is connected to the first end of the load circuit 102, so as to output the input voltage of the power supply 101 on the second end of the first switch to the load circuit 102, so that the load circuit 102 can work normally.

[0051] When the third end of the third switch tube is at the second level at the second end of the load circuit 102, that is, when the level state provided by the load circuit 102 to the third end of the third switch tube is the second level, the first end and the second end of the third switch tube will be triggered to shut down, so as to shut down the first end and the second end of the second switch tube, thereby effectively avoiding affecting the good and stable operation of the load circuit 102.

[0052] Optionally, the first level may be a high level, and the second level may be a corresponding low level; or, the second level may be a high level, and the first level may be a corresponding low level, which is not limited in the present application.

[0053] Optionally, the second switch tube is any one of a PNP transistor, an NPN transistor, a P-type thin film transistor, a P-type field effect transistor, an N-type thin film transistor and an N-type field effect transistor, which is not limited in the present application.

[0054] Optionally, the third switch tube is an NPN transistor, a P-type thin film transistor or a P-type field effect transistor, which is not limited in the present application.

[0055] It is worth mentioning that the NPN transistor is valid at a low level, and the signal forms a switch with 0V; the PNP transistor is valid at a high level, and the signal forms a switch with 24V.

[0056] Preferably, the first switch tube 211 is a P-channel metal oxide semiconductor field effect transistor; the second switch tube is a PNP transistor; and the third switch tube is an NPN transistor.

[0057] It is understandable that, since the resistance between the drain and the source of the first switch tube 211 is very small when it is saturated and turned on, there is a very small voltage drop at a large current, so the loss is also very small, so that it can work normally even at a low voltage; after the input voltage through the first switch tube 211 is filtered by the filter circuit 24, it can supply power to other modules in the load circuit 102; and by using the second switch tube and the third switch tube, the first switch tube 211 and the load circuit 102 are isolated and on-off controlled, so that when the third end of the load circuit 102 is fed to the third end of the third switch tube at the first level, the load circuit 102 is powered to drive the load circuit 102 to work normally, and there is no nonlinear voltage drop that affects the good and stable operation of the load circuit 102.

[0058] See also Figure 3 , Figure 3 It is a structural schematic diagram of the third embodiment of the anti-reverse connection circuit of the present application.

[0059] In this embodiment, the anti-reverse connection circuit 30 specifically includes a switch circuit 31, a soft start circuit 32, a voltage clamp circuit 33, a filter circuit 34 and an isolation switch circuit 35; and the switch circuit 31 further includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a first switch tube Q1; the soft start circuit 32 includes a fifth capacitor C5; the voltage clamp circuit 33 includes a first resistor R1 and a Zener diode D1; the filter circuit 34 includes a first inductor L1, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8 and a ninth capacitor C9; the isolation switch circuit 35 includes a second switch tube Q2, a third switch tube Q3, a second resistor R2, a third resistor R3, a tenth capacitor C10, a fourth resistor R4 and an eleventh capacitor C11.

[0060] Among them, the first end of the first capacitor C1 is coupled to the first end BAT of the power supply (not shown in the figure), the first end of the second capacitor C2 and the first end of the first switch tube Q1, the second end of the first capacitor C1 is coupled to the first end of the third capacitor C3, the second end of the third capacitor C3 is grounded, the second end of the second capacitor C2 is coupled to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is grounded.

[0061] The second end of the first switch tube Q1 is coupled to the second end of the Zener diode D1, the second end of the fifth capacitor C5 and the first end of the first inductor L1, the third end of the first switch tube Q1 is coupled to the first end of the first resistor R1, the second end of the first resistor R1 is coupled to the first end of the Zener diode D1, the first end of the fifth capacitor C5 and grounded.

[0062] Furthermore, the second end of the first inductor L1 is coupled to the second end VDD of the power supply, the first end of the sixth capacitor C6, the first end of the eighth capacitor C8 and the first end of the second switch tube Q2, the second end of the sixth capacitor C6 is coupled to the first end of the seventh capacitor C7, the second end of the seventh capacitor C7 is grounded, the second end of the eighth capacitor C8 is coupled to the first end of the ninth capacitor C9, and the second end of the ninth capacitor C9 is grounded.

[0063] Further, the second end of the second switch tube Q2 is coupled to the first end of the second resistor R2, the third end of the second switch tube Q2 is coupled to the first end of the third switch tube Q3, the second end of the third switch tube Q3 is grounded, the third end of the third switch tube Q3 is coupled to the second end VCC of the load circuit (not shown), the second end of the second resistor R2 is coupled to the first end of the third resistor R3, the first end of the tenth capacitor C10 and the first end of the fourth resistor R4, the second end of the third resistor R3 is coupled to the second end of the tenth capacitor C10 and the second end of the eleventh capacitor C11 and is grounded, and the second end of the fourth resistor R4 is coupled to the first end of the eleventh capacitor C11 and the first end FZ of the load circuit.

[0064] Optionally, the first switch tube Q1 is a P-channel metal oxide semiconductor field effect transistor; the second switch tube Q2 is a PNP transistor; and the third switch tube Q3 is an NPN transistor.

[0065] It is understandable that, since the resistance between the drain and the source of the first switch tube Q1 is very small when it is saturated and turned on, there is a very small voltage drop at a large current, so the loss is also very small, so that it can work normally even at a low voltage; after the input voltage through the first switch tube Q1 is filtered by the filter circuit 34, it can supply power to other modules in the load circuit; and by using the second switch tube Q2 and the third switch tube Q3, the first switch tube Q1 is isolated and on-off controlled from the load circuit, so that when the second end VCC of the load circuit is fed to the third end of the third switch tube Q3 at the first level, the first end FZ of the load circuit is supplied with power to drive the load circuit to work normally, and there is no nonlinear voltage drop that affects the good and stable operation of the load circuit.

[0066] This application also provides a power supply circuit, see Figure 4 , Figure 4 1 is a schematic diagram of a power circuit of the present application. In this embodiment, the power circuit 40 includes: a power supply 41, an anti-reverse connection circuit 42 and a load circuit 43, wherein the anti-reverse connection circuit 42 is coupled between the power supply 41 and the load circuit 43.

[0067] The anti-reverse connection circuit 42 may be the anti-reverse connection circuit 10, the anti-reverse connection circuit 20, or the anti-reverse connection circuit 30 as described above. Figure 1-Figure 3 And the related text content will not be repeated here.

[0068] This application also provides an electronic device, see Figure 5 , Figure 5 1 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. In this embodiment, the electronic device 50 includes a housing 51 and a functional circuit 52 connected to the housing 51 .

[0069] The functional circuit 52 may be the anti-reverse connection circuit 10, the anti-reverse connection circuit 20, the anti-reverse connection circuit 30, or the power supply circuit 40 as described above. Figure 1-Figure 4 And the related text content will not be repeated here.

[0070] Different from the prior art, the switch circuit in the anti-reverse connection circuit provided by the present application includes a first switch tube, a body diode is provided inside the first switch tube, a first end of the first switch tube is coupled to an external power supply, a second end of the first switch tube is coupled to an external load circuit, and a third end of the first switch tube is grounded, so that when the input voltage of the power supply input to the first switch tube is a forward voltage, the body diode can be triggered to conduct, so as to increase the voltage between the first end and the third end of the first switch tube to a first threshold voltage, thereby conducting the first end and the second end of the first switch tube to form a fully conductive path, providing the input voltage to the load circuit, and at the output When the input voltage is a negative voltage, the body diode is triggered to turn off, so that the first end and the second end of the first switch tube are in a completely off state, and no conduction path can be formed, thereby effectively disconnecting the conductive connection between the power supply and the load circuit, so that when a large current is applied, the power supply voltage drop can be controlled within a certain range, so that the load circuit in a low-voltage state can also work normally; and whether it is a large current or a small current input, a large working error of the load circuit is avoided to ensure good performance; in addition, the power loss of the anti-reverse connection circuit is also small, thereby effectively reducing the risk of device loss or even burning caused by the power loss being converted into heat loss.

[0071] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A reverse connection protection circuit, characterized in that: The anti-reverse connection circuit comprises: The switch circuit comprises a first switch tube, wherein a body diode is provided inside the first switch tube, a first end of the first switch tube is coupled to an external power supply, a second end of the first switch tube is coupled to an external load circuit, and a third end of the first switch tube is grounded; Among them, when the input voltage input by the power supply to the first switch tube is a forward voltage, the body diode is triggered to turn on to increase the voltage between the first end and the third end of the first switch tube to a first threshold voltage, thereby turning on the first end and the second end of the first switch tube to provide the input voltage to the load circuit; when the input voltage is a negative voltage, the body diode is triggered to turn off to turn off the first end and the second end of the first switch tube, thereby disconnecting the conductive connection between the power supply and the load circuit.

2. The anti-reverse connection circuit according to claim 1, characterized in that: The anti-reverse connection circuit also includes a soft start circuit, which is coupled between the second end and the third end of the first switch tube so that when the voltage between the first end and the third end of the first switch tube is increased to a second threshold voltage, the first end and the second end of the first switch tube are triggered to be turned on; wherein the second threshold voltage is greater than the first threshold voltage.

3. The anti-reverse connection circuit according to claim 1, characterized in that: The anti-reverse connection circuit also includes a voltage clamping circuit, which is coupled between the second end and the third end of the first switch tube to limit the voltage between the first end and the third end of the first switch tube to a set voltage value.

4. The anti-reverse connection circuit according to claim 3, characterized in that: The voltage clamping circuit includes a first resistor and a Zener diode, wherein the first end of the first resistor is coupled to the third end of the first switch tube, the second end of the first resistor is coupled to the first end of the Zener diode and is grounded, and the second end of the Zener diode is coupled to the second end of the first switch tube and the load circuit.

5. The anti-reverse connection circuit according to claim 1, characterized in that: The anti-reverse connection circuit also includes a filter circuit, which is coupled between the second end of the first switch tube and the load circuit to receive the input voltage sent by the first switch tube, filter the input voltage, and then send it to the load circuit.

6. The anti-reverse connection circuit according to claim 1, characterized in that: The switch circuit also includes a first capacitor and a second capacitor, wherein the first end of the first capacitor is coupled to the power supply, the first end of the second capacitor and the first end of the first switch tube, the second end of the first capacitor is grounded, and the second end of the second capacitor is grounded.

7. The anti-reverse connection circuit according to any one of claims 1 to 6, characterized in that: The anti-reverse connection circuit further includes an isolation switch circuit, the isolation switch circuit includes a second switch tube and a third switch tube, the first end of the second switch tube is coupled to the second end of the first switch tube, the second end of the second switch tube is coupled to the first end of the load circuit, the third end of the second switch tube is coupled to the first end of the third switch tube, the second end of the third switch tube is grounded, and the third end of the third switch tube is coupled to the second end of the load circuit; Among them, when the second end of the load circuit is at the first level, the third end of the third switch tube triggers the first end and the second end of the third switch tube to be turned on, so as to turn on the first end and the second end of the second switch tube, thereby connecting the second end of the first switch to the first end of the load circuit.

8. The anti-reverse connection circuit according to any one of claims 1 to 6, characterized in that: The first switch tube is a P-channel metal oxide semiconductor field effect transistor.

9. A power supply circuit, characterized in that: The power supply circuit comprises: a power supply source, an anti-reverse connection circuit and a load circuit, wherein the anti-reverse connection circuit is coupled between the power supply source and the load circuit, and the load circuit is coupled to an external load circuit; Wherein, the anti-reverse connection circuit is the anti-reverse connection circuit as described in any one of claims 1-8.

10. An electronic device, characterized in that: The electronic device comprises a housing and a functional circuit connected to the housing; Wherein, the functional circuit is the anti-reverse connection circuit as described in any one of claims 1 to 8, or the power supply circuit as described in claim 9.

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