CN222169303U - Overvoltage and undervoltage protection circuit, voltage control device and electronic equipment - Google Patents

Abstract

The application provides an overvoltage and undervoltage protection circuit, a voltage control device and electronic equipment, the overvoltage and undervoltage protection circuit comprises a voltage division unit, a comparison unit, a first switch unit and a second switch unit. The voltage dividing unit is used for dividing the power supply voltage, the comparing unit is used for outputting a first level signal to the first switching unit when the power supply voltage is larger than or equal to the overvoltage protection voltage or smaller than or equal to the undervoltage protection voltage and outputting a second level signal to the first switching unit when the power supply voltage is smaller than the overvoltage protection voltage and larger than the undervoltage protection voltage, the first switching unit is used for being turned off when the first level signal is received and being turned on when the second level signal is received, and the second switching unit is used for being turned off when the first switching unit is turned on. The overvoltage and undervoltage protection circuit has simpler circuit design and lower circuit cost.

Description

Overvoltage and undervoltage protection circuit, voltage control device and electronic equipment

Technical Field

The present application relates to the field of electronic circuits, and in particular, to an overvoltage and undervoltage protection circuit, a voltage control device, and an electronic device.

Background

Currently, all circuits have a voltage operating range, and once the voltage operating range is exceeded, overvoltage or undervoltage occurs. Over-voltage and under-voltage can cause the circuit to be abnormal or to be in fault. Therefore, it is necessary to provide an overvoltage protection unit and an undervoltage protection unit in the circuit.

However, the current over-voltage protection unit and under-voltage protection unit have complicated circuit designs and high costs.

Disclosure of utility model

The application mainly aims to provide an overvoltage and undervoltage protection circuit, a voltage control device and electronic equipment, and aims to solve the problems that the current overvoltage protection unit and undervoltage protection unit are complex in circuit design and high in cost.

In a first aspect, the application provides an overvoltage and undervoltage protection circuit, which comprises a voltage dividing unit, a comparison unit, a first switch unit and a second switch unit;

the input end of the voltage dividing unit is used for receiving a power supply voltage, and the voltage dividing unit is used for dividing the power supply voltage;

The input end of the comparison unit is connected with the first voltage division end of the voltage division unit, and the output end of the comparison unit is connected with the first end of the first switch unit; the comparison unit is used for outputting a first level signal to the first switch unit when the power supply voltage is greater than or equal to the overvoltage protection voltage or when the power supply voltage is less than or equal to the undervoltage protection voltage; the comparison unit is further used for outputting a second level signal to the first switch unit when the power supply voltage is smaller than the overvoltage protection voltage and larger than the undervoltage protection voltage;

The second end of the first switch unit is connected with the first end of the second switch unit, and the third end of the first switch unit is used for being grounded;

the second end of the second switch unit is used for connecting a load, the third end of the second switch unit is connected with the input end of the voltage dividing unit, and the second switch unit is used for being turned off when the first switch unit is turned off and turned on when the first switch unit is turned on.

In a second aspect, an embodiment of the present application further provides a voltage control apparatus, including:

The voltage conversion circuit is used for receiving a power supply voltage and performing voltage conversion on the power supply voltage;

the control circuit is connected with the voltage conversion unit and used for controlling the voltage conversion unit;

The overvoltage and undervoltage protection circuit according to any one of the embodiments of the present application is connected to a power supply terminal of the control circuit, and is used for supplying power to the control circuit.

In a third aspect, an embodiment of the present application further provides an electronic device, including:

A power interface;

The overvoltage and undervoltage protection circuit according to any one of the embodiments of the present application is connected to the power interface.

The embodiment of the application provides an overvoltage and undervoltage protection circuit which comprises a voltage dividing unit, a comparison unit, a first switch unit and a second switch unit. The voltage dividing unit is used for dividing the power supply voltage. The comparison unit is used for outputting a first level signal to the first switch unit when the power supply voltage is larger than or equal to the overvoltage protection voltage or when the power supply voltage is smaller than or equal to the undervoltage protection voltage. The comparison unit is also used for outputting a second level signal to the first switch unit when the power supply voltage is smaller than the overvoltage protection voltage and larger than the undervoltage protection voltage. The first switch unit is used for being turned off when receiving a first level signal and turned on when receiving a second level signal. The first end of the second switch unit is connected with the first switch unit, the second end of the second switch unit is used for being connected with a load, and the third end of the second switch unit is used for being connected with a power supply voltage. The second switch unit is used for being turned off when the first switch unit is turned off and being turned on when the first switch unit is turned on. The first switch unit is turned off when receiving the first level signal, and the second switch unit is turned off along with the turn-off of the first switch unit, so that a path of a power supply voltage flowing to a load is turned off, and overvoltage protection or undervoltage protection can be provided. The overvoltage and undervoltage protection circuit provided by the embodiment of the application has simpler circuit design and does not need higher circuit cost, so that the problem of higher cost can be solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic circuit diagram of an embodiment of an over-voltage and under-voltage protection circuit according to an embodiment of the present application;

FIG. 2 is a schematic circuit diagram of a voltage divider unit according to an embodiment of the present application;

FIG. 3 is a schematic circuit diagram of another embodiment of a voltage divider unit according to an embodiment of the present application;

FIG. 4 is a schematic circuit diagram of a comparison unit according to an embodiment of the present application;

FIG. 5 is a schematic circuit diagram of an embodiment of a voltage dividing unit and a comparing unit according to the present application;

Fig. 6 is a schematic circuit diagram of an implementation of the first switch unit according to an embodiment of the present application;

FIG. 7 is a schematic circuit diagram of an embodiment of a voltage dividing unit, a comparing unit and a first switch unit according to the present application;

Fig. 8 is a schematic circuit diagram of an implementation of the second switch unit according to an embodiment of the present application;

FIG. 9 is a schematic circuit diagram of another embodiment of an over-voltage and under-voltage protection circuit according to an embodiment of the present application;

FIG. 10 is a schematic block diagram of a voltage control apparatus according to an embodiment of the present application;

FIG. 11 is a schematic circuit diagram of a voltage control apparatus according to an embodiment of the present application;

Fig. 12 is a schematic block diagram of an electronic device according to an embodiment of the present application.

The achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

It should be noted that the terms "first" and "second" in the description and claims of the present application and the accompanying drawings are used to distinguish similar objects, and are not used to describe a specific order or sequence.

It should be further noted that, in the method disclosed in the embodiment of the present application or the method shown in the flowchart, one or more steps for implementing the method are included, and the execution order of the steps may be interchanged with each other, where some steps may be deleted without departing from the scope of the claims.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

Referring to fig. 1, fig. 1 is a schematic circuit diagram of an embodiment of an over-voltage and under-voltage protection circuit according to an embodiment of the present application.

As shown in fig. 1, the overvoltage/undervoltage protection circuit 100 includes a voltage dividing unit 110, a comparing unit 120, a first switching unit 130, and a second switching unit 140.

The input end of the voltage dividing unit 110 is used for receiving the supply voltage Vg, and the voltage dividing unit 110 is used for dividing the supply voltage Vg. An input terminal of the comparing unit 120 is connected to a first voltage dividing terminal of the voltage dividing unit 110, and an output terminal of the comparing unit 120 is connected to a first terminal of the first switching unit 130. The comparison unit 120 is configured to output a first level signal to the first switch unit 130 when the supply voltage Vg is greater than or equal to the overvoltage protection voltage, or when the supply voltage Vg is less than or equal to the undervoltage protection voltage. The comparing unit 120 is further configured to output a second level signal to the first switching unit 130 when the supply voltage Vg is less than the overvoltage protection voltage and greater than the undervoltage protection voltage.

The second end of the first switch unit 130 is connected to the first end of the second switch unit 140, and the third end of the first switch unit 130 is grounded. The first switch unit 130 is configured to be turned off when receiving the first level signal and turned on when receiving the second level signal. A second terminal of the second switching unit 140 is used for connecting the load 10, and a third terminal of the second switching unit 140 is connected to an input terminal of the voltage dividing unit 110. The second switching unit 140 is configured to be turned off when the first switching unit 130 is turned off and turned on when the first switching unit 130 is turned on.

It should be noted that, the supply voltage Vg may be input from an external power source, or may be input from an internal power source in the device. The load 10 may be an external consumer or other load in the same device. The overvoltage protection voltage and the undervoltage protection voltage may be preset, and the overvoltage protection voltage is greater than the undervoltage protection voltage.

After dividing the supply voltage Vg, the voltage dividing unit 110 outputs the divided supply voltage Vg to the comparing unit 120. The comparison unit 120 outputs a first level signal, for example, a low level signal, when the supply voltage Vg is greater than or equal to the overvoltage protection voltage. When the supply voltage Vg is less than or equal to the under-voltage protection voltage, the comparison unit 120 may output a low-level signal as the supply voltage Vg is a small-signal voltage. In contrast, when the supply voltage Vg is smaller than the overvoltage protection voltage and greater than the undervoltage protection voltage, the supply voltage Vg may be confirmed as the normal operation voltage, and thus the second level signal output from the comparison unit 120 to the first switch unit 130 is, for example, a high level signal.

It should be noted that, when the first switch unit 130 is turned off when receiving the first level signal, the second switch unit 140 is turned off along with the turning off of the first switch unit 130, so that the path of the supply voltage Vg flowing to the load 10 is turned off, and thus overvoltage protection or under-voltage protection can be provided. The first switch unit 130 is turned on when receiving the second level signal, and the second switch unit 140 is turned on along with the conduction of the first switch unit 130, so that a path of the supply voltage Vg flowing to the load 10 is turned on, so that the load 10 can operate normally. Therefore, the circuit design of the overvoltage and undervoltage protection circuit 100 provided by the embodiment of the application is simpler, and higher circuit cost is not needed, so that the problem of higher cost can be solved.

In an embodiment, referring to fig. 2, fig. 2 is a schematic circuit diagram of a voltage dividing unit according to an embodiment of the application. As shown in fig. 2, the voltage dividing unit 110 includes a resistor Ra and a resistor Rb. The first terminal of the resistor Ra is used as an input terminal of the voltage dividing unit 110 for receiving the supply voltage Vg. The second end of the resistor Ra and the first end of the resistor Rb may be used as the first voltage dividing end Ve1 of the voltage dividing unit 110, and the second end of the resistor Rb is grounded.

In an embodiment, referring to fig. 3, fig. 3 is a schematic circuit diagram of another implementation of the voltage dividing unit according to the embodiment of the present application. As shown in fig. 3, the voltage dividing unit 110 includes a second resistor R1, a third resistor R2, and a fourth resistor R3. The first end of the second resistor R1 is used for receiving the supply voltage Vg, the second end of the second resistor R1 is connected with the first end of the third resistor R2, the second end of the third resistor R2 is connected with the first end of the fourth resistor R3, and the two ends of the fourth resistor R3 are grounded. The second end of the second resistor R1 is used as the second voltage dividing end Ve2 of the voltage dividing unit 110, and the second end of the third resistor R2 is used as the first voltage dividing end Ve1 of the voltage dividing unit 110.

It should be noted that the resistance values of the second resistor R1, the third resistor R2, and the fourth resistor R3 may be adjusted according to actual situations. For example, the resistance values of the second resistor R1, the third resistor R2, and the fourth resistor R3 may be determined according to the reference voltage of the first voltage dividing terminal Ve 1.

It is understood that the second resistor R1, the third resistor R2, and the fourth resistor R3 may be each composed of one or more resistors. The voltage dividing unit 110 may further include other resistors or other devices, which are not particularly limited in the embodiment of the present application.

In an embodiment, please refer to fig. 4, fig. 4 is a schematic circuit diagram of an implementation of the comparing unit according to an embodiment of the present application. As shown in fig. 4, the comparison unit 120 includes a controllable precision voltage-stabilizing source D1. The reference electrode of the controllable precision voltage stabilizing source D1 is used as an input end of the comparing unit 120 and is connected with the first voltage dividing end Ve1 of the voltage dividing unit 110. The cathode of the controllable precise voltage stabilizing source D1 is grounded. The anode of the controllable precision voltage stabilizing source D1 is connected to the first end Vr of the first switch unit 130 as the output end of the comparing unit 120. The anode of the controllable precision voltage stabilizing source D1 is further connected to the second voltage dividing end Ve2 of the voltage dividing unit 110.

It should be noted that, the first voltage dividing end Ve1 of the voltage dividing unit 110 is configured to output a reference voltage to the reference electrode of the controllable precision voltage stabilizing source D1, where the reference voltage may be determined according to the overvoltage protection voltage. The controllable precision regulated source D1 may be turned on when the supply voltage Vg is greater than or equal to the overvoltage protection voltage, thereby outputting a first level signal to the first switching unit 130. The controllable precision voltage stabilizing source D1 may also be turned off when the supply voltage Vg is less than or equal to the under-voltage protection voltage, so as to output a first level signal to the first switch unit 130. The controllable precision voltage stabilizing source D1 may also output a second level signal to the first switch unit 130 when the supply voltage Vg is less than the overvoltage protection voltage and greater than the undervoltage protection voltage.

It should be noted that, the controllable precise voltage stabilizing source D1 is used as the comparing unit 120, no additional reference source is needed, the circuit is simple, the devices are few, and no high circuit cost is needed. Meanwhile, the problem that no actual reference level can be used for overvoltage and undervoltage protection before power-on can be avoided.

For example, the controllable precision voltage-stabilizing source D1 is TL431, and TL431 is used as the comparator. The internal reference level of TL431 is 2.5V, i.e. the reference voltage of the reference electrode is 2.5V. And when the divided power supply voltage Vg is smaller than 2.5V, the D1 is turned off, and a first level signal is output to the second switch unit 140 through the anode of the controllable precise voltage stabilizing source D1. When the divided supply voltage Vg is greater than or equal to 2.5V, D1 is turned on, and a first level signal is output to the first switch unit 130 through the anode of the controllable precision voltage stabilizing source D1. In addition, when the supply voltage Vg is less than or equal to the under-voltage protection voltage, the D1 is turned off, but since the voltage value of the supply voltage Vg at this time is small, the first level signal is also output to the second switch unit 140 through the anode of the controllable precision voltage stabilizing source D1.

In an embodiment, the comparing unit 120 may also include other comparators, such as differential comparators, operational amplifier comparators, and the like. The comparing unit 120 may include a reference terminal for inputting a reference voltage, so as to output a corresponding first level signal or a second level signal under the different comparison result between the supply voltage Vg and the overvoltage protection voltage and the undervoltage protection voltage, which is not particularly limited in the embodiment of the present application.

In an embodiment, as shown in fig. 4, the comparing unit 120 further includes a first resistor R5, a first end of the first resistor R5 is connected to the second voltage-dividing end Ve2 of the voltage-dividing unit 110, and a second end of the first resistor R5 is connected to the anode of the controllable precision voltage-stabilizing source D1. The first resistor R5 can divide the power supply voltage Vg, so that a protection effect can be provided for the controllable precise voltage stabilizing source D1.

In one embodiment, as shown in fig. 5, the overvoltage/undervoltage protection circuit 100 further includes a power-on delay unit, and the power-on delay unit includes a first capacitor C2. The first end of the first capacitor C2 is connected to the second voltage dividing end Ve2 of the voltage dividing unit 110, and the second end of the first capacitor C2 is grounded.

When the supply voltage Vg is connected to the overvoltage/undervoltage protection circuit 100, the first capacitor C2 needs to be charged first, so as to provide a power-on delay function. The power-on delay unit is arranged to better protect the good work of circuit devices, so that transient faults are not easy to occur.

For example, as shown in fig. 5, when the supply voltage Vg is just accessed, the voltage of the second voltage dividing terminal Ve2 is 0, and the voltage c1 is also 0.Vg charges the capacitor C1 through the resistor R1, thereby providing a power-on delay function. It should be noted that, changing the resistance values of the resistors R1 and R5 and the size of the capacitor C1 may change the delay time of power-up.

In an embodiment, referring to fig. 6, fig. 6 is a schematic circuit diagram of an implementation of a first switch unit according to an embodiment of the present application. As shown in fig. 6, the first switching unit 130 includes an NMOS transistor Q1 and a fifth resistor R7. The gate of the NMOS transistor Q1 is connected to the output terminal of the comparing unit 120 as the first terminal Vr of the first switching unit 130. The drain of the NMOS transistor Q1 is connected to the first end of the second switching unit 140 as the second end Va of the first switching unit 130. The source of the NMOS transistor Q1 is used as the third terminal of the first switch unit 130 for grounding. The fifth resistor R7 is connected between the gate and the drain of the NMOS transistor Q1.

The fifth resistor R7 is a voltage stabilizing resistor. The NMOS transistor Q1 may be turned off when receiving the first level signal and turned on when receiving the second level signal. For example, the NMOS transistor Q1 is turned off when receiving a low level signal and turned on when receiving a high level signal. It is to be understood that the first switch unit 130 may further include other components such as a resistor, and the first switch unit 130 may also include switching devices such as a triode and a PMOS tube, which is not particularly limited in the embodiment of the present application.

In an embodiment, as shown in fig. 7, the overvoltage/undervoltage protection circuit 100 further includes a power-on delay unit, where the power-on delay unit includes a second capacitor C2, and the second capacitor C2 is connected in parallel with a fifth resistor R7. When the supply voltage Vg is connected to the overvoltage/undervoltage protection circuit 100, the second capacitor needs to be charged first, so as to provide a power-on delay function. The power-on delay unit is arranged to better protect the good work of circuit devices, so that transient faults are not easy to occur.

For example, as shown in fig. 7, when the supply voltage Vg is just accessed, the Vr terminal voltage is 0, Q1 is turned off, vg charges the capacitor C2 through the resistors R1 and R5, and when the Vr terminal voltage reaches the on level of Q1, Q1 is turned on. The time for the point B to reach the conduction level of Q2 can be adjusted by changing the resistance values of the resistors R1, R5 and the like and the size of the capacitor C2, so that the power-on delay time is changed.

In an embodiment, as shown in fig. 8, the second switch unit 140 includes a PMOS transistor Q2, a sixth resistor R6, and a seventh resistor R4. The first terminal of the sixth resistor R6 is connected to the second terminal Va of the first switching unit 130 as the first terminal of the second switching unit 140. The second end of the sixth resistor R6 is connected with the grid electrode of the PMOS tube Q2. The drain of the PMOS transistor Q2 is used as the second terminal Vb of the second switching unit 140 for connecting the load 10. The source of the PMOS transistor Q2 is connected to the input terminal of the voltage dividing unit 110 as the third terminal of the second switch unit 140, so as to be capable of being connected to the supply voltage Vg. The seventh resistor R4 is connected between the gate and the drain of the PMOS transistor Q2.

The sixth resistor R6 is a voltage dividing resistor, the seventh resistor R4 is a voltage stabilizing resistor, and the sixth resistor R6 and the seventh resistor R4 can each provide a protection function. The PMOS transistor Q2 is turned off when the first switching unit 130 is turned off, and turned on when the first switching unit 130 is turned on. It is to be understood that the second switching unit 140 may be an NMOS transistor, and the second switching unit 140 may further include other components such as a resistor, and the second switching unit 140 may also include a switching device such as a triode, which is not specifically limited in the embodiment of the present application.

In the overvoltage/undervoltage protection circuit 100 described in the above embodiment, the first switch unit 130 is turned off when receiving the first level signal, and the second switch unit 140 is turned off along with the turn-off of the first switch unit 130, so that the path of the supply voltage Vg to the load 10 is turned off, and thus overvoltage protection or undervoltage protection can be provided. The first switch unit 130 is turned on when receiving the second level signal, and the second switch unit 140 is turned on along with the conduction of the first switch unit 130, so that a path of the supply voltage Vg flowing to the load 10 is turned on, so that the load 10 can operate normally. Therefore, the circuit design of the overvoltage and undervoltage protection circuit 100 provided by the embodiment of the application is simpler, and higher circuit cost is not needed, so that the problem of higher cost can be solved.

An overvoltage/undervoltage protection circuit according to an embodiment of the present application will be described below with reference to fig. 9.

As shown in fig. 9, the supply voltage Vg is, for example, the supply voltage VCC, and the load RL. D1 adopts TL431 as a comparator, the internal reference level of TL431 is 2.5V, that is, the reference voltage at point a is 2.5V, D1 is turned off when <2.5V, and D1 is turned on when 2.5V or more.

When VCC is over-voltage, the voltage at the point A is more than 2.5V after being divided by the resistors R1 and R2, D1 is conducted, the point B is low level, Q1 is turned off, and the point C is high level, so that Q2 is turned off to realize the over-voltage protection function.

Under-voltage, when VCC voltage is too low, A point voltage is less than 2.5V, D1 is high resistance, B point voltage is not up to the on voltage of Q1 after being divided by resistors (R1, R2, R3, R5 and R7), Q2 is always in an off state, and VCC cannot be loaded on load RL.

When the voltage A is less than 2.5V, D1 is turned off, the grid electrode of Q2 is high level after the voltage is divided by resistors (R1, R2, R3, R5 and R7), Q1 is conducted, the voltage at point C is low level after the voltage is divided by R4 and R6, Q2 (P tube) is conducted, and VCC is loaded on load RL.

It should be noted that the overvoltage and undervoltage protection circuit provided by the embodiment of the application has the advantages of low cost, simple circuit, few devices, no need of adding additional reference sources and power-on delay.

Referring to fig. 10, fig. 10 is a schematic block diagram of a voltage control apparatus according to an embodiment of the application.

As shown in fig. 10, the voltage control apparatus 200 includes:

A voltage conversion circuit 210 for receiving a power supply voltage and for performing voltage conversion on the power supply voltage;

a control circuit 220 connected to the voltage conversion unit 210 for controlling the voltage conversion unit 210;

The overvoltage/undervoltage protection circuit 230 in the above embodiment is connected to the power terminal of the control circuit 220, and is used for supplying power to the control circuit 220.

The over-voltage and under-voltage protection circuit 230 may be the over-voltage and under-voltage protection circuit 100 described in the above embodiment. The control circuit 220 may include a control chip, and the voltage conversion circuit 210 may include a transformer, and may include other devices, which is not limited in particular by the embodiment of the present application.

As illustrated in fig. 11, the voltage control apparatus 200 may be a flyback power supply that includes a voltage conversion circuit 210, a control circuit 220, and an overvoltage/undervoltage protection circuit 230. The input terminal of the voltage conversion circuit 210 is used for being connected to the supply voltage VBUS, and the voltage conversion circuit 210 includes a transformer T1. The input end of the overvoltage/undervoltage protection circuit 230 is also used for connecting to the supply voltage VBUS, and the output end of the overvoltage/undervoltage protection circuit 230 is used for outputting the target voltage VCC. The control circuit 220 includes a control chip U1 and a third switch Q3. The output end of the overvoltage and undervoltage protection circuit 230 is connected to the power end of the control chip U1. When the supply voltage VBUS is over-voltage or under-voltage, the over-voltage and under-voltage protection circuit 230 is in an off state, so that the power supply to the control chip U1 is turned off, and the third switch Q3 is turned off, so that the voltage conversion circuit 210 does not operate. When the supply voltage VBUS is a normal operating voltage, the overvoltage/undervoltage protection circuit 230 provides the target voltage VCC to the control chip U1, and the control chip U1 outputs an enable signal, such as a pwm signal, to the third switch Q3, so as to control the on time of the third switch Q3, so that the voltage conversion circuit 210 can perform voltage conversion on the supply voltage VBUS.

That is, as shown in fig. 11, when VBUS voltage is normal, the voltage of C1 is divided to make the voltage of Q1 on C1 load on C2 as VCC, VCC is used for U1 starting, and the transformer T1 works after U1 starting. The secondary coil of the transformer T1 is connected with Q2 through a diode D2, so that the secondary of the transformer T1 is continuously supplied with power, the long-term operation of U1 is ensured, and a closed loop is formed. When VBUS is over-voltage, D1 is conducted to enable the grid electrode of Q1 to be pulled down to be changed into low level Q1 to be turned off, so that the voltage VCC of Q2 is turned off, continuous power supply cannot be obtained, U1 stops working, and the transformer stops energy transmission. When VBUS voltage is too low, Q1 cannot conduct so that U1 cannot start.

It can be understood that the beneficial effects of the electronic device provided by the embodiment of the present application can refer to the beneficial effects of the overvoltage/undervoltage protection circuit provided in the corresponding embodiment, and are not described herein.

Referring to fig. 12, fig. 12 is a schematic block diagram of an electronic device according to an embodiment of the application.

As shown in fig. 12, the electronic device 300 includes:

The power interface 310 and the over-voltage and under-voltage protection circuit 320 described in the above embodiments, the over-voltage and under-voltage protection circuit 320 is connected to the power interface.

The power interface 310 may be a power input interface or a power output interface. When the power interface 310 is a power input interface, it may be used to connect to an external power source, so that a supply voltage can be provided to the overvoltage/undervoltage protection circuit 320 through the power interface 310. When the power interface 310 is a power output interface, it may be used to connect a load so that power can be provided to the load through the power interface 310. The over-voltage and under-voltage protection circuit 320 may be the over-voltage and under-voltage protection circuit 100 described in the above embodiment.

In one embodiment, the electronic device 300 further includes an internal power source, such as a battery module, including one or more electrical energy storage units, such as one or more batteries. The plurality of batteries can be connected in series and parallel to form the battery module.

It can be understood that the beneficial effects of the electronic device provided by the embodiment of the present application can refer to the beneficial effects of the overvoltage/undervoltage protection circuit provided in the corresponding embodiment, and are not described herein.

In the description of the present application, it should be noted that the terms "mounted," "connected," and "coupled" are to be construed broadly, as well as, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically indicated and defined. It may be a mechanical connection that is made, or may be an electrical connection. Can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The above disclosure provides many different embodiments, or examples, for implementing different structures of the application. The foregoing description of specific example components and arrangements has been presented to simplify the present disclosure. They are, of course, merely examples and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The embodiments of the present application have been described in detail with reference to the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present application.

Claims (10)

1. The overvoltage and undervoltage protection circuit is characterized by comprising a voltage dividing unit, a comparison unit, a first switch unit and a second switch unit;

the input end of the voltage dividing unit is used for receiving a power supply voltage, and the voltage dividing unit is used for dividing the power supply voltage;

The input end of the comparison unit is connected with the first voltage division end of the voltage division unit, and the output end of the comparison unit is connected with the first end of the first switch unit; the comparison unit is used for outputting a first level signal to the first switch unit when the power supply voltage is greater than or equal to the overvoltage protection voltage or when the power supply voltage is less than or equal to the undervoltage protection voltage; the comparison unit is further used for outputting a second level signal to the first switch unit when the power supply voltage is smaller than the overvoltage protection voltage and larger than the undervoltage protection voltage;

The second end of the first switch unit is connected with the first end of the second switch unit, and the third end of the first switch unit is used for being grounded;

the second end of the second switch unit is used for connecting a load, the third end of the second switch unit is connected with the input end of the voltage dividing unit, and the second switch unit is used for being turned off when the first switch unit is turned off and turned on when the first switch unit is turned on.

2. The overvoltage/undervoltage protection circuit of claim 1, wherein the comparison unit comprises a controllable precision voltage stabilizing source;

The reference electrode of the controllable precise voltage stabilizing source is used as the input end of the comparison unit;

The anode of the controllable precise voltage stabilizing source is used as the output end of the comparison unit, and the anode of the controllable precise voltage stabilizing source is also connected with the second voltage dividing end of the voltage dividing unit.

3. The overvoltage/undervoltage protection circuit of claim 2, wherein the comparison unit further comprises a first resistor, a first end of the first resistor is connected to a second voltage dividing end of the voltage dividing unit, and a second end of the first resistor is connected to an anode of the controllable precision voltage stabilizing source.

4. The overvoltage/undervoltage protection circuit of claim 2, wherein the voltage dividing unit comprises a second resistor, a third resistor, and a fourth resistor;

The first end of the second resistor is used for receiving a power supply voltage, the second end of the second resistor is connected with the first end of the third resistor, the second end of the third resistor is connected with the first end of the fourth resistor, and the two ends of the fourth resistor are grounded;

The second end of the second resistor is used as a second voltage dividing end of the voltage dividing unit, and the second end of the third resistor is used as a first voltage dividing end of the voltage dividing unit.

5. The overvoltage/undervoltage protection circuit of claim 2, further comprising a power-up delay unit comprising a first capacitor;

The first end of the first capacitor is connected with the second voltage division end of the voltage division unit, and the second end of the first capacitor is grounded.

6. The overvoltage undervoltage protection circuit of any one of claims 1-5, wherein the first switching unit comprises an NMOS transistor and a fifth resistor, wherein a gate of the NMOS transistor is used as a first terminal of the first switching unit, a drain of the NMOS transistor is used as a second terminal of the first switching unit, and a source of the NMOS transistor is used as a third terminal of the first switching unit;

The fifth resistor is connected between the grid electrode and the drain electrode of the NMOS tube.

7. The over-voltage and under-voltage protection circuit of claim 6, further comprising a power-up delay unit comprising a second capacitor connected in parallel with the fifth resistor.

8. The overvoltage/undervoltage protection circuit of any one of claims 1-5, wherein the second switching unit comprises a PMOS transistor, a sixth resistor, and a seventh resistor;

The first end of the sixth resistor is used as the first end of the second switch unit, and the second end of the sixth resistor is connected with the grid electrode of the PMOS tube;

The drain electrode of the PMOS tube is used as the second end of the second switch unit, and the source electrode of the PMOS tube is used as the third end of the second switch unit;

the seventh resistor is connected between the grid electrode and the drain electrode of the PMOS tube.

9. A voltage control apparatus, comprising:

The voltage conversion circuit is used for receiving a power supply voltage and performing voltage conversion on the power supply voltage;

the control circuit is connected with the voltage conversion unit and used for controlling the voltage conversion unit;

The overvoltage and undervoltage protection circuit of any one of claims 1-8, connected to a power supply terminal of the control circuit, for powering the control circuit.

10. An electronic device, comprising:

A power interface;

The overvoltage and undervoltage protection circuit of any one of claims 1-8, connected to the power interface.