CN216959294U - Overvoltage protection circuit and electronic equipment - Google Patents

Abstract

The present application belongs to the technical field of circuit protection, and provides an overvoltage protection circuit and electronic equipment, wherein the overvoltage protection circuit includes an overvoltage detection circuit, an overvoltage discharge circuit, an enabling drive circuit, and a power supply circuit. The detection circuit is used to generate an overvoltage protection signal when the input voltage of the power input interface is greater than a preset threshold voltage, the overvoltage relief circuit is used to generate a shutdown signal according to the overvoltage protection signal, and the enable drive circuit is used to output the enable The signal is sent to the enable terminal of the power supply circuit, and the power supply voltage is output to the power input terminal of the power supply circuit. The power supply circuit is used for voltage conversion of the power supply voltage to output the working voltage required for the operation of the electronic equipment, and after receiving a shutdown When the signal is cut off, the output of the working voltage is stopped, and the above-mentioned overvoltage protection circuit can solve the problem that a large voltage is easily generated after the power supply of the existing electronic equipment is powered on, thereby damaging the electronic equipment.

Description

Overvoltage protection circuits and electronic equipment

technical field

The present application belongs to the technical field of circuit protection, and in particular relates to an overvoltage protection circuit and electronic equipment.

Background technique

Cars have become an increasingly household choice. During the use of the car, due to reasons such as long-term non-use or failure to turn off the on-board electrical appliances in time, the car battery will be insufficient or even under-voltage, resulting in the problem that the car cannot be started normally. The battery protector is used to charge the car battery after voltage conversion of the DC power input by the DC power supply, so as to supplement the battery power.

However, the existing battery protector has the problem that a large voltage is easily generated after the power is turned on, thereby damaging the battery protector. Similar electronic devices also have corresponding problems, that is, when the power supply is powered on, the power input interface generates a large voltage, which damages the electronic device.

Utility model content

In order to solve the above technical problems, the embodiments of the present application provide an overvoltage protection circuit and an electronic device, which can solve the problem that the existing electronic device is prone to generate a large voltage after being powered on, thereby damaging the electronic device.

A first aspect of the embodiments of the present application provides an overvoltage protection circuit, which is applied to an electronic device. The overvoltage protection circuit includes: an overvoltage detection circuit, an overvoltage relief circuit, an enabling drive circuit, and a power supply circuit;

The detection end of the overvoltage detection circuit is used for connecting with the power input interface of the electronic device, and the overvoltage detection circuit is used for generating overvoltage protection when the input voltage of the power input interface is greater than a preset threshold voltage Signal;

The input end of the overvoltage relief circuit is connected to the output end of the overvoltage detection circuit, the output end of the overvoltage relief circuit is connected to the enabling end of the power supply circuit, and the overvoltage relief circuit is connected to the enabling end of the power supply circuit. The ground end of the circuit is grounded, and the overvoltage relief circuit is used for discharging the input voltage when receiving the overvoltage protection signal, and generating a shutdown signal to the power supply according to the overvoltage protection signal The enable terminal of the supply circuit;

The input end of the enabling drive circuit is connected to the power input interface, the first output end of the enabling drive circuit is connected to the power supply input end of the power supply circuit, and the second output end of the enabling drive circuit is connected The terminal is connected to the enable terminal of the power supply circuit, and the enable drive circuit is used to output an enable signal to the enable terminal of the power supply circuit according to the input voltage of the power input interface, and output a supply voltage to a power input end of the power supply circuit;

The power supply circuit is configured to perform voltage conversion on the power supply voltage to output a working voltage required for the operation of the electronic device when receiving the enable signal, and stop outputting when receiving the shutdown signal the operating voltage.

In one embodiment, the overvoltage detection circuit includes a first voltage regulator; wherein,

The negative electrode of the first voltage regulator is connected to the power input interface, and the positive electrode of the first voltage regulator is connected to the overvoltage discharge circuit.

In one embodiment, the enabling driving circuit includes: a first voltage dividing unit and a second voltage dividing unit; wherein,

The first end of the first voltage dividing unit is connected to the power input interface, and the second end of the first voltage dividing unit is connected to the first end of the second voltage dividing unit; the second voltage dividing unit The first end of the unit is also connected to the first output end of the enabling drive circuit; the second end of the second voltage dividing unit is connected to the second output end of the enabling drive circuit.

In one embodiment, the enabling driving circuit further includes: a first filtering circuit; wherein,

The first end of the first filter circuit is connected to the second end of the first voltage dividing unit, the second end of the first filter circuit is grounded, and the first filter circuit is used for the power supply circuit The voltage of the power input terminal is regulated and filtered.

In one embodiment, the first voltage dividing unit includes a first resistor and a third resistor; the second voltage dividing unit includes a second resistor; wherein,

The first end of the first resistor is connected to the power input interface, the second end of the first resistor is connected to the power input end of the power supply circuit, and the third resistor is connected in parallel with the first resistor ;

The first end of the second resistor is connected to the power input end of the power supply circuit, and the second end of the second resistor is connected to the enable end of the power supply circuit.

In one embodiment, the overvoltage discharge circuit includes: a fourth resistor, a fifth resistor, a fourth capacitor, and a first switch tube; wherein,

The first end of the fourth resistor is connected to the output end of the overvoltage detection circuit, the second end of the fourth resistor is connected to the control end of the first switch tube, and the fourth capacitor is connected in parallel with the between the control end and the first end of the first switch tube, the fifth resistor is connected in parallel between the control end and the first end of the first switch tube, and the first end of the first switch tube is grounded, The second end of the first switch tube is connected to the enable end of the power supply circuit.

In one embodiment, the power supply circuit includes: a voltage stabilizing unit and a second filtering unit; a power input terminal of the voltage stabilizing unit is connected to a first output terminal of the enabling drive circuit, and the voltage stabilizing unit The enable terminal of the voltage regulator unit is connected to the second output terminal of the enable drive circuit, the enable terminal of the voltage regulator unit is also connected to the output terminal of the overvoltage discharge circuit, and the output terminal of the voltage regulator unit is connected to the output terminal of the overvoltage discharge circuit. The first end of the second filtering unit is connected, and the second end of the second filtering unit is grounded.

In one embodiment, the power supply circuit further includes: a noise bypass unit; a first end of the noise bypass unit is connected to a noise bypass end of the voltage regulator unit, and a first end of the noise bypass unit is connected to the noise bypass end of the voltage regulator unit. The two terminals are grounded, and the noise bypass unit is used to reduce the output noise of the voltage regulator unit.

A second aspect of the embodiments of the present application provides an electronic device, including: a power input interface and the overvoltage protection circuit according to any one of the above; the power input interface and a first end of the overvoltage protection circuit connect.

In one embodiment, the electronic device further includes: a voltage conversion circuit and a power output interface; the power output interface is connected to the second end of the overvoltage protection circuit;

The input end of the voltage conversion circuit is connected with the output end of the power input interface, the working power end of the voltage conversion circuit is connected with the output end of the power supply circuit, and the output end of the voltage conversion circuit is connected with the output end of the power supply circuit. The power output interface is connected, and the voltage conversion circuit is used for converting the input voltage to generate a target output voltage to the power output interface.

Embodiments of the present application provide an overvoltage protection circuit and an electronic device, wherein the overvoltage protection circuit includes: an overvoltage detection circuit, an overvoltage discharge circuit, an enabling drive circuit, and a power supply circuit; wherein the overvoltage The detection circuit is used to generate an overvoltage protection signal when the input voltage of the power input interface is greater than a preset threshold voltage, and the overvoltage relief circuit is used to receive the overvoltage protection signal, and generate a shutdown signal to the power supply according to the overvoltage protection signal The enable terminal of the circuit, the enable drive circuit is used to output the enable signal to the enable terminal of the power supply circuit according to the input voltage of the power input interface, and to output the power supply voltage to the power input terminal of the power supply circuit. The power supply circuit is used for When the enable signal is received, the power supply voltage is transformed to output the working voltage required for the operation of the electronic equipment, and when the shutdown signal is received, the output of the working voltage is stopped. The above-mentioned overvoltage protection circuit can solve the problem of the existing electronic equipment. There is a problem that a large voltage is easily generated after the power supply is powered on, thereby damaging the electronic equipment.

Description of drawings

1 is a schematic structural diagram of an overvoltage protection circuit provided by an embodiment of the present application;

2 is a specific schematic diagram of a circuit principle of an overvoltage protection circuit provided by an embodiment of the present application;

FIG. 3 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

It is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top" , "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which are only for the convenience of describing the application and simplifying the description, rather than indicating or implying the indicated device. Or elements must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of this application, "plurality" means one or more than one, unless expressly and specifically defined otherwise.

With the improvement of people's living standards and the rapid development of the automobile industry, users use cars more frequently, which also puts forward higher requirements for the charging technology of automobile batteries. Most of the batteries used to charge the car are charged by direct charging. The use of direct charging can greatly improve the charging speed of the battery, but there are also certain safety hazards. For example, when the power supply input side circuit cannot supply power, the power supply output side The circuit will generate a large voltage on the input side circuit of the power supply, which may cause a large voltage shock to the battery protector, which may eventually lead to damage to the battery protector, or even a fire. Similar electronic equipment will also have corresponding problems, that is, when the power supply is powered on When the power input interface generates a large voltage and damages the electronic equipment.

In order to solve the above technical problems, an embodiment of the present application provides an overvoltage protection circuit, which is applied to electronic equipment. Referring to FIG. 1 , the overvoltage protection circuit includes: an overvoltage detection circuit 20 , an overvoltage relief circuit 40 , a The circuit 30 and the power supply circuit 50 can be driven.

Specifically, the detection end of the overvoltage detection circuit 20 is connected to the power input interface 10 of the electronic device, and the overvoltage detection circuit 20 is configured to generate an overvoltage protection signal when the input voltage of the power input interface 10 is greater than a preset threshold voltage , the input end of the overvoltage relief circuit 40 is connected to the output end of the overvoltage detection circuit 20 , the output end of the overvoltage relief circuit 40 is connected to the enable end of the power supply circuit 50 , and the ground end of the overvoltage relief circuit 40 Grounding, the overvoltage discharge circuit 40 is used to discharge the input voltage when receiving the overvoltage protection signal, and generate a shutdown signal to the enable terminal of the power supply circuit 50 according to the overvoltage protection signal; enable the drive circuit 30 The input end of the drive circuit 30 is connected to the power input interface 10 , the first output end of the enable drive circuit 30 is connected to the power input end of the power supply circuit 50 , the second output end of the enable drive circuit 30 is connected to the enable end of the power supply circuit 50 The connection and enable drive circuit 30 is used to output an enable signal to the enable terminal of the power supply circuit 50 according to the input voltage of the power input interface 10, and to output the power supply voltage to the power input terminal of the power supply circuit 50. The power supply circuit 50 uses When receiving the enable signal, the power supply voltage is transformed to output the working voltage required by the electronic device, and when the off signal is received, the outputting of the working voltage is stopped.

In this embodiment, the overvoltage detection circuit 20 can compare the input voltage of the power input interface 10 with a preset threshold voltage, and generate an overvoltage protection signal when the input voltage of the power input interface 10 is greater than the preset threshold voltage . When the input voltage of the power input interface 10 is greater than the preset threshold voltage, it means that there is a large voltage in the circuit. If the large voltage enters the electronic equipment at this time, the electronic equipment will be damaged. At this time, the overvoltage detection circuit 20 generates an overvoltage protection signal.

In this embodiment, the overvoltage relief circuit 40 is configured to receive the overvoltage protection signal and generate a shutdown signal according to the overvoltage protection signal, and the power supply circuit 50 stops outputting the operating voltage when receiving the shutdown signal. Specifically, after the overvoltage relief circuit 40 receives the overvoltage protection signal, it means that overvoltage occurs in the circuit. At this time, the overvoltage relief circuit 40 generates a shutdown signal, so that the power supply circuit 50 stops working and stops outputting the working voltage. The electronic equipment can be effectively protected, and the electronic equipment can be prevented from being damaged, and the problem that a large voltage is easily generated after the power supply of the existing electronic equipment is powered on, thereby damaging the electronic equipment.

In this embodiment, the enable driving circuit 30 is used to supply power to the power supply circuit 50 , and outputs an enable signal to the enable terminal of the power supply circuit 50 according to the input voltage of the power input interface 10 to control the output of the power supply circuit 50 Operating Voltage. Specifically, the input terminal of the enabling drive circuit 30 is connected to the power input interface 10 , the first output terminal of the enabling driving circuit 30 is connected to the power input terminal VIN of the power supply circuit 50 , and the second output terminal of the enabling driving circuit 30 is connected to the enable terminal EN of the power supply circuit 50, and the enable drive circuit 30 is used for outputting an enable signal to the enable terminal EN of the power supply circuit 50 according to the input voltage of the power input interface 10, and outputting the power supply voltage to the power supply circuit 50 is the power input terminal VIN. The power supply circuit 50 is used to convert the power supply voltage to output the working voltage required for the operation of the electronic device when receiving the enable signal, and stop outputting the working voltage when receiving the shutdown signal, so as to realize the existence of the input voltage In case of overvoltage, the electronic equipment is disconnected to protect the electronic equipment and other associated equipment.

In one embodiment, as shown in FIG. 2 , the overvoltage detection circuit 20 includes a first voltage regulator D1.

Specifically, the negative electrode of the first voltage regulator D1 is connected to the power input interface 10 , and the positive electrode of the first voltage regulator D1 is connected to the overvoltage relief circuit 40 . When the power input interface 10 is connected to an external power supply, and the voltage of the external power supply exceeds a preset threshold voltage, that is, an overvoltage, the first voltage regulator D1 is turned on, thereby generating an overvoltage protection signal, and the overvoltage relief circuit 40 After receiving the overvoltage protection signal, a shutdown signal is generated according to the overvoltage protection signal to control the power supply circuit 50 to stop outputting the working voltage, which solves the problem that the existing electronic equipment is prone to generate a large voltage after the power is turned on, thereby damaging the electronic equipment. question.

In one embodiment, the first Zener tube D1 has forward conduction, reverse cut-off, and unidirectional conductivity. If the reverse voltage on the first Zener tube D1 exceeds the bearing capacity of the first Zener tube D1, That is, when the reverse voltage exceeds the preset threshold voltage, the first Zener tube D1 will be broken down. Although the first Zener tube D1 is in a breakdown state and passes a large current, it will not be damaged, and this phenomenon The repeatability is very good. As long as the first voltage regulator tube D1 is in the breakdown state, although the electricity flowing through the tube changes greatly, the voltage across the tube changes very little, which plays a role in voltage regulation. Set the first voltage regulator The tube D1 can detect the overvoltage phenomenon in the circuit in time to prevent the electronic equipment from being damaged.

In one embodiment, as shown in FIG. 2 , the enabling driving circuit 30 includes: a first voltage dividing unit 31 and a second voltage dividing unit 32 .

Specifically, the first end of the first voltage dividing unit 31 is connected to the power input interface 10 , the second end of the first voltage dividing unit 31 is connected to the first end of the second voltage dividing unit 32 , and the second voltage dividing unit 32 The first terminal is also connected to the first output terminal of the enabling drive circuit 30, the second terminal of the second voltage dividing unit 32 is connected to the second output terminal of the enabling driving circuit 30, the first voltage dividing unit 31 and the second voltage dividing unit 32 are connected The unit 32 is configured to perform voltage division processing on the voltage signal input by the power input interface 10 to form a corresponding voltage at the power input terminal and the enable terminal of the power supply circuit 50 .

In this embodiment, when the power input interface 10 is connected to an external power supply, the first voltage dividing unit 31 and the second voltage dividing unit 32 perform voltage dividing processing on the voltage signal input by the power input interface 10 to generate a suitable power supply circuit 50 to supply power to the power supply circuit 50, so that the power supply circuit 50 can work normally. For example, when the power input interface 10 inputs a voltage, the first voltage dividing unit 31 and the second voltage dividing unit 32 start to divide the input voltage, output an enable signal to the enable terminal of the power supply circuit 50, and output The power supply voltage is applied to the power input terminal of the power supply circuit 50, and the power supply circuit 50 starts to work normally and outputs the working voltage.

In one embodiment, referring to FIG. 2 , the enabling driving circuit 30 further includes: a first filtering circuit 33 .

Specifically, the first end of the first filter circuit 33 is connected to the second end of the first voltage dividing unit 31 , the second end of the first filter circuit 33 is grounded, and the first filter circuit 33 is used to supply power to the power supply circuit 50 The voltage at the input terminal is regulated and filtered. The provision of the first filter circuit 33 can reduce the AC component in the voltage of the power supply interface of the power supply circuit 50 and retain the DC component, so that the ripple coefficient of the output voltage is reduced and the waveform becomes smoother.

In one embodiment, as shown in FIG. 2 , the first voltage dividing unit 31 includes a first resistor R1 and a third resistor R3 ; the second voltage dividing unit 32 includes a second resistor R2 .

Specifically, the first end of the first resistor R1 is connected to the power input interface 10, the second end of the first resistor R1 is connected to the power input end of the power supply circuit 50, the third resistor R3 is connected in parallel with the first resistor R1, the second The first end of the resistor R2 is connected to the power input end of the power supply circuit 50 , and the second end of the second resistor R2 is connected to the enable end of the power supply circuit 50 .

In this embodiment, when the power input interface 10 is connected to an external power supply, the first resistor R1 , the second resistor R2 and the third resistor R3 divide the voltage signal input from the power input interface 10 to generate a suitable power supply circuit. 50 to supply power to the power supply circuit 50 so that the power supply circuit 50 can work normally. Among them, the third resistor R3 is connected in parallel with the first resistor R1, and the third resistor R3 is set in parallel with the first resistor R1. Its function is that when the first resistor R1 fails, the third resistor R3 is connected in series with the second resistor R2, and is responsible for the The voltage signal input by the power input interface 10 performs a voltage division function, or when the third resistor R3 fails, the first resistor R1 and the second resistor R2 are connected in series to perform a voltage division function on the voltage signal input by the power input interface 10 . In other embodiments, the first voltage dividing unit 31 may also be set according to voltage dividing requirements, for example, only one resistor is set, or a plurality of resistors are connected in series and parallel to form.

In one embodiment, as shown in FIG. 2 , the first filter circuit 33 includes: a first capacitor C1 , a second capacitor C2 and a third capacitor C3 .

Specifically, the first end of the first capacitor C1, the first end of the second capacitor C2, and the first end of the third capacitor C3 are commonly connected to the second end of the first voltage dividing unit 31, and the second end of the first capacitor C1 terminal, the second terminal of the second capacitor C2 and the second terminal of the third capacitor C3 are all grounded, and the first capacitor C1, the second capacitor C2 and the third capacitor C3 are used to stabilize the voltage of the input terminal of the power supply circuit 50 filter processing.

In this embodiment, when the power input interface 10 is connected to an external power supply, the first capacitor C1, the second capacitor C2 and the third capacitor C3 perform voltage stabilization and filtering on the voltage of the power supply interface of the power supply circuit 50, and the first capacitor C1, the second capacitor C2 and the third capacitor C3 can reduce the AC component in the circuit and retain its DC component, so that the output voltage ripple coefficient is reduced, the waveform becomes smoother, and the power supply circuit 50 can work normally.

In one embodiment, as shown in FIG. 2 , the overvoltage relief circuit 40 includes: a fourth resistor R4 , a fifth resistor R5 , a fourth capacitor C4 and a first switch transistor Q1 .

Specifically, the first end of the fourth resistor R4 is connected to the output end of the overvoltage detection circuit 20, the second end of the fourth resistor R4 is connected to the control end of the first switch tube, and the fourth capacitor is connected in parallel with the first switch tube. Between the control end and the first end, the fifth resistor is connected in parallel between the control end and the first end of the first switch tube, the first end of the first switch tube is grounded, and the second end of the first switch tube is connected to the power supply circuit The enable terminal of 50 is connected.

In this embodiment, the fourth resistor R4 and the fifth resistor R5 are used to divide the voltage of the overvoltage protection signal. Different switch units have different on and off voltage values. By setting the fourth resistor R4 and the fifth resistor R5 The resistor R4 and the fifth resistor R5 can divide the voltage of the overvoltage protection signal to ensure that the voltage of the overvoltage protection signal meets the on and off requirements of the switch unit, so that the first switch tube Q1 can be accurately After receiving the overvoltage protection signal, the first switch transistor Q1 is used to generate a shutdown signal according to the overvoltage protection signal to control whether the power supply circuit 50 outputs the working voltage, thereby ensuring that when an overvoltage occurs in the circuit, the first switch transistor Q1 By generating the shutdown signal, the power supply circuit 50 does not output the working voltage, which solves the problem that the existing electronic equipment is prone to generate a large voltage after being powered on, thereby damaging the electronic equipment.

In this embodiment, the fourth capacitor C4 is used to stabilize the voltage of the control terminal of the first switch tube Q1 to ensure that the first switch tube Q1 can be stably turned off or turned on.

In one embodiment, as shown in FIG. 2 , the power supply circuit 50 includes: a voltage regulator unit 51 and a second filter unit 52 .

Specifically, the power supply input end of the voltage stabilization unit 51 is connected to the output end of the enabling drive circuit 30 , the enabling end of the voltage stabilization unit 51 is connected to the first output end of the enabling drive circuit 30 , and the enabling end of the voltage stabilization unit It is connected to the second output end of the enabling drive circuit 30 , the enabling end of the voltage stabilization unit 51 is also connected to the output end of the overvoltage discharge circuit 40 , and the output end of the voltage stabilization unit 51 is connected to the first output end of the second filtering unit 52 . terminal is connected, and the second terminal of the second filtering unit 52 is grounded.

In this embodiment, the voltage stabilizing unit 51 is used for outputting the working voltage according to the enable signal, and stops outputting the working voltage according to the shutdown signal, and the second filtering unit 52 is used for filtering the working voltage output by the voltage stabilizing unit 51 .

In one embodiment, as shown in FIG. 2 , the power supply circuit 50 further includes: a noise bypass unit 53 .

Specifically, the first end of the noise bypass unit 53 is connected to the noise bypass end BP of the voltage stabilization unit 51 , the second end of the noise bypass unit 53 is grounded, and the noise bypass unit 53 is used to reduce the output of the voltage stabilization unit 51 noise.

In one embodiment, as shown in FIG. 2 , the first switch transistor Q1 is an NMOS transistor.

In this embodiment, the gate of the NMOS transistor corresponds to the control terminal of the first switch transistor Q1 and is connected to the fourth resistor R4 and the fifth resistor R5, and the drain of the NMOS transistor corresponds to the second terminal of the first switch transistor Q1 and the power supply The supply circuit 50 is connected, and the source of the NMOS transistor corresponds to the first end of the first switch transistor Q1 to be grounded. When the input voltage of the power input interface 10 is greater than the preset threshold voltage, an overvoltage protection signal is generated, the overvoltage protection signal is a high level signal, and the overvoltage protection signal is sent to the NMOS through the fourth resistor R4 and the fifth resistor R5 The control terminal of the tube, the NMOS tube is turned on, and the level of the enable terminal EN of the power supply circuit 50 is pulled down to a low level, that is, a low-level shutdown signal is formed, and the power supply circuit 50 stops outputting the working voltage. The problem that the existing electronic equipment is likely to generate a large voltage after the power supply is powered on, thereby damaging the electronic equipment, is avoided.

In one embodiment, the overvoltage detection circuit 20 and the enabling driving circuit 30 are connected to the power input interface 10 of the electronic device through the signal line BUS+.

The embodiment of the present application also provides an electronic device, as shown in FIG. 3 , including: a power input interface 10 and an overvoltage protection circuit as described above; wherein the power input interface 10 and the first one of the overvoltage protection circuit end connection.

In one embodiment, as shown in FIG. 3 , the electronic device further includes: a voltage conversion circuit 60 and a power output interface 70 .

Specifically, the input end of the voltage conversion circuit 60 is connected to the output end of the power input interface 10 , the working power end of the voltage conversion circuit 60 is connected to the output end of the power supply circuit 50 , and the output end of the voltage conversion circuit 60 is connected to the power output interface 70 The power output interface is connected to the second end of the overvoltage protection circuit, and the voltage conversion circuit 60 is used for converting the input voltage to generate a target output voltage to the power output interface 70 .

In this embodiment, the voltage conversion circuit 60 converts the working voltage output by the overvoltage protection circuit and sends it to the power output interface 70 .

The electronic device may be a voltage conversion device, which is used to convert the voltage input by the external power supply and output it to supply power to the target device. In one embodiment, the electronic device may be a battery conditioner. Taking the battery protector as an example, when the input voltage of the power input interface 10 is greater than the preset threshold voltage, it means that there is a large voltage in the circuit. If the battery is charged at this time, the battery protector will be damaged. The overvoltage detection circuit 20 generates an overvoltage protection signal. After receiving the overvoltage protection signal, the overvoltage relief circuit 40 generates a shutdown signal according to the overvoltage protection signal to control the power supply circuit 50 to stop outputting the working voltage. At this time, the voltage conversion circuit 60 does not receive the signal. The working voltage is in the non-working state, that is, the voltage output by the power input interface 10 will not be converted, and the working voltage signal will not be generated and sent to the power output interface 70, which solves the problem that the existing battery protector is easy to generate after the power is turned on. The problem of high voltage and damage to the battery protector.

The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application, and should be included in the application. within the scope of protection.

Claims (10)

1. An overvoltage protection circuit applied to an electronic device, the overvoltage protection circuit comprising: the overvoltage protection circuit comprises an overvoltage detection circuit, an overvoltage discharge circuit, an enable driving circuit and a power supply circuit;

the overvoltage detection circuit is used for generating an overvoltage protection signal when the input voltage of the power input interface is greater than a preset threshold voltage;

the input end of the overvoltage bleeder circuit is connected with the output end of the overvoltage detection circuit, the output end of the overvoltage bleeder circuit is connected with the enabling end of the power supply circuit, the grounding end of the overvoltage bleeder circuit is grounded, and the overvoltage bleeder circuit is used for discharging the input voltage when receiving the overvoltage protection signal and generating a turn-off signal to the enabling end of the power supply circuit according to the overvoltage protection signal;

the input end of the enable driving circuit is connected with the power input interface, the first output end of the enable driving circuit is connected with the power input end of the power supply circuit, the second output end of the enable driving circuit is connected with the enable end of the power supply circuit, and the enable driving circuit is used for outputting an enable signal to the enable end of the power supply circuit according to the input voltage of the power input interface and outputting a power supply voltage to the power input end of the power supply circuit;

the power supply circuit is used for converting the voltage of the power supply voltage to output the working voltage required by the work of the electronic equipment when receiving the enabling signal, and stopping outputting the working voltage when receiving the turn-off signal.

2. The overvoltage protection circuit according to claim 1, wherein said overvoltage detection circuit comprises a first voltage regulator tube; wherein,

the negative electrode of the first voltage-stabilizing tube is connected with the power input interface, and the positive electrode of the first voltage-stabilizing tube is connected with the overvoltage bleeder circuit.

3. The overvoltage protection circuit of claim 1, wherein the enable driver circuit comprises: a first voltage dividing unit and a second voltage dividing unit; wherein,

the first end of the first voltage division unit is connected with the power input interface, and the second end of the first voltage division unit is connected with the first end of the second voltage division unit; the first end of the second voltage division unit is also connected with the first output end of the enabling drive circuit; and the second end of the second voltage division unit is connected with the second output end of the enabling drive circuit.

4. The overvoltage protection circuit of claim 3, wherein the enable driver circuit further comprises: a first filter circuit; wherein,

the first end of the first filter circuit is connected with the second end of the first voltage division unit, the second end of the first filter circuit is grounded, and the first filter circuit is used for performing voltage stabilization filtering processing on the voltage of the power supply input end of the power supply circuit.

5. The overvoltage protection circuit of claim 3, wherein the first voltage divider block includes a first resistor and a third resistor; the second voltage division unit comprises a second resistor; wherein,

the first end of the first resistor is connected with the power input interface, the second end of the first resistor is connected with the power input end of the power supply circuit, and the third resistor is connected with the first resistor in parallel;

the first end of the second resistor is connected with the power input end of the power supply circuit, and the second end of the second resistor is connected with the enable end of the power supply circuit.

6. The overvoltage protection circuit of claim 1, wherein the overvoltage relief circuit comprises: the fourth resistor, the fifth resistor, the fourth capacitor and the first switch tube; wherein,

the first end of the fourth resistor is connected with the output end of the overvoltage detection circuit, the second end of the fourth resistor is connected with the control end of the first switch tube, the fourth capacitor is connected in parallel between the control end and the first end of the first switch tube, the fifth resistor is connected in parallel between the control end and the first end of the first switch tube, the first end of the first switch tube is grounded, and the second end of the first switch tube is connected with the enabling end of the power supply circuit.

7. The overvoltage protection circuit of claim 1, wherein the power supply circuit comprises: the voltage stabilizing unit and the second filtering unit; the power input end of the voltage stabilizing unit is connected with the first output end of the enabling drive circuit, the enabling end of the voltage stabilizing unit is connected with the second output end of the enabling drive circuit, the enabling end of the voltage stabilizing unit is further connected with the output end of the overvoltage bleeder circuit, the output end of the voltage stabilizing unit is connected with the first end of the second filtering unit, and the second end of the second filtering unit is grounded.

8. The overvoltage protection circuit of claim 7, wherein said power supply circuit further comprises: a noise bypass unit; the first end of the noise bypass unit is connected with the noise bypass end of the voltage stabilizing unit, the second end of the noise bypass unit is grounded, and the noise bypass unit is used for reducing the output noise of the voltage stabilizing unit.

9. An electronic device, comprising: a power input interface and an overvoltage protection circuit as claimed in any one of claims 1 to 8; the power input interface is connected with the first end of the overvoltage protection circuit.

10. The electronic device of claim 9, wherein the electronic device further comprises: the voltage conversion circuit and the power output interface; the power output interface is connected with the second end of the overvoltage protection circuit;

the input end of the voltage conversion circuit is connected with the output end of the power input interface, the working power end of the voltage conversion circuit is connected with the output end of the power supply circuit, the output end of the voltage conversion circuit is connected with the power output interface, and the voltage conversion circuit is used for converting the input voltage to generate a target output voltage to the power output interface.

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