Over-voltage and under-voltage protection circuit, vehicle-mounted power supply and vehicle

Abstract

The utility model discloses an overvoltage and undervoltage protection circuit, a vehicle-mounted power supply and a vehicle, the overvoltage and undervoltage protection circuit comprises a voltage detection circuit, a voltage conversion circuit, a reference voltage circuit and a comparison circuit, the input end of the voltage detection circuit is electrically connected to a to-be-detected voltage port; the first output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit, the second output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit through the voltage conversion circuit, and the output end of the reference voltage circuit is electrically connected to the second input end of the comparison circuit. And comparing the voltage of the first input end of the comparison circuit to be greater than the voltage of the second input end of the comparison circuit so as to trigger circuit protection. According to the overvoltage and undervoltage protection circuit, overvoltage and undervoltage circuit protection is completed by only using one comparator, the number of circuit devices is reduced, the circuit design is simplified, and circuit integration and miniaturization of a vehicle-mounted power supply are facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit protection, in particular to an over-voltage and under-voltage protection circuit, a vehicle-mounted power supply and a vehicle. Background Art

[0002] Many electronic devices will encounter high voltage or low voltage during use. When running under high voltage, the electronic device may be burned, and when working under low voltage, it will affect the service life of the electronic device. Over-voltage and under-voltage protection circuits can protect electronic devices from damage due to overvoltage or failure to output due to undervoltage.

[0003] Usually, the over-voltage and under-voltage protection circuit includes both an over-voltage comparison circuit and an under-voltage comparison circuit, which requires at least two comparators, has many peripheral devices, a complex circuit, and a high production cost. Utility Model Content

[0004] A series of simplified concepts are introduced in the utility model content section, which will be further described in detail in the detailed implementation section. The utility model content section of the utility model does not mean to attempt to define the key features and essential technical features of the technical solution claimed for protection, nor does it mean to attempt to determine the scope of protection of the technical solution claimed for protection.

[0005] The utility model provides an over-voltage and under-voltage protection circuit, comprising a voltage detection circuit, a voltage conversion circuit, a reference voltage circuit and a comparison circuit, wherein the input end of the voltage detection circuit is electrically connected to a voltage port to be detected, the first output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit, the second output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit via the voltage conversion circuit, the output end of the reference voltage circuit is electrically connected to the second input end of the comparison circuit, and the voltage of the first input end of the comparison circuit is compared to be greater than the voltage of the second input end of the comparison circuit to trigger circuit protection.

[0006] Exemplarily, based on whether the voltage detection circuit outputs a voltage to the voltage conversion circuit, the voltage conversion circuit selectively outputs a high level or a low level.

[0007] Exemplarily, the voltage detection circuit includes at least a Zener diode, which is turned on when the voltage value of the voltage port to be detected is greater than the undervoltage protection voltage, and is not turned on when the voltage value of the voltage port to be detected is less than the undervoltage protection voltage.

[0008] Exemplarily, the voltage detection circuit also includes a voltage divider circuit, which includes at least two voltage divider resistors connected in series, the first output end of the voltage detection circuit is arranged between the at least two resistors, the voltage regulator is connected in parallel with one of the at least two voltage divider resistors, and the second output end of the voltage detection circuit is used to output the divided voltage.

[0009] Exemplarily, the voltage conversion circuit includes at least a transistor:

[0010] When the second output terminal of the voltage detection circuit outputs a voltage to the voltage conversion circuit, the transistor is turned on and the voltage conversion circuit outputs a low level;

[0011] When the second output terminal of the voltage detection circuit does not output a voltage to the voltage conversion circuit, the transistor is turned off, and the voltage conversion circuit outputs a high level.

[0012] Exemplarily, the transistor includes two input terminals and one output terminal, the two input terminals of the transistor are respectively connected to the second output terminal and the voltage terminal of the voltage detection circuit, the output terminal of the transistor is grounded, and the output terminal of the voltage conversion circuit is arranged between the transistor and the voltage terminal.

[0013] Exemplarily, the voltage at the first input terminal of the comparison circuit is the voltage at the first output terminal of the voltage detection circuit or the voltage at the output terminal of the voltage conversion circuit.

[0014] Exemplarily, the comparison circuit includes at least a comparator and an output controller.

[0015] Based on comparing the voltage of the first input terminal of the comparison circuit with the voltage of the second input terminal of the comparison circuit, the comparator outputs a high level or a low level;

[0016] Based on the level of the comparator output, the output controller is turned on or off;

[0017] When the output controller is turned on, circuit protection is triggered;

[0018] When the output controller is turned off, the circuit protection is not triggered.

[0019] Exemplarily, the output terminal of the reference voltage circuit provides a stable reference voltage to the second input terminal of the comparison circuit, wherein:

[0020] The reference voltage circuit includes a three-terminal regulator and three resistors connected in series, wherein a first lead terminal and a second lead terminal of the three-terminal regulator are electrically connected to adjacent resistors respectively, and a third lead terminal of the three-terminal regulator is grounded.

[0021] The utility model also provides a vehicle-mounted power supply, comprising any of the over-voltage and under-voltage protection circuits described above.

[0022] The utility model also provides a vehicle, comprising the above-mentioned vehicle-mounted power supply.

[0023] According to the over- and under-voltage protection circuit, vehicle-mounted power supply and vehicle provided by the utility model, the first output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit, the second output end of the voltage detection circuit is also electrically connected to the first input end of the comparison circuit via the voltage conversion circuit, and the output end of the reference voltage circuit is electrically connected to the second input end of the comparison circuit, and then the voltage at the first input end of the comparison circuit is compared with the voltage at the second input end of the comparison circuit to determine whether to trigger circuit protection. The over- and under-voltage protection circuit only uses one comparator to complete the circuit protection of overvoltage and undervoltage, reduces the number of circuit components, simplifies the circuit design, and is conducive to the integration of circuits and the miniaturization of vehicle-mounted power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings of the present invention are used as a part of the present invention for understanding the present invention. The drawings show the embodiments of the present invention and their descriptions, and are used to explain the principle of the present invention.

[0025] In the attached figure:

[0026] Figure 1 Schematic diagram of an over-voltage and under-voltage protection circuit according to an embodiment of the utility model.

[0027] Reference numerals

[0028] 110. Voltage detection circuit 120. Voltage conversion circuit

[0029] 130. Reference voltage circuit 140. Comparison circuit

[0030] 111. Voltage port to be detected

[0031] 112. The first output terminal of the voltage detection circuit

[0032] 113. The second output terminal of the voltage detection circuit

[0033] 141. The first input terminal of the comparison circuit

[0034] 142. The second input terminal of the comparison circuit DETAILED DESCRIPTION

[0035] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the utility model, some technical features known in the art are not described.

[0036] In order to thoroughly understand the present invention, a detailed description will be provided in the following description to illustrate the over-voltage and under-voltage protection circuit, vehicle power supply and vehicle of the present invention. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the art of circuit protection technology. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of the features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0038] Now, exemplary embodiments according to the present utility model will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present utility model thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of layers and regions is exaggerated, and the same reference numerals are used to represent the same elements, and thus their description will be omitted.

[0039] The utility model provides an over-voltage and under-voltage protection circuit. Figure 1As shown, it includes a voltage detection circuit 110, a voltage conversion circuit 120, a reference voltage circuit 130 and a comparison circuit 140, the input end of the voltage detection circuit 110 is electrically connected to a voltage port 111 to be detected, the first output end 112 of the voltage detection circuit 110 is electrically connected to a first input end 141 of the comparison circuit 140, the second output end 113 of the voltage detection circuit 110 is electrically connected to the first input end 141 of the comparison circuit 140 via the voltage conversion circuit 120, the output end of the reference voltage circuit 130 is electrically connected to the second input end 142 of the comparison circuit 140, and the voltage of the first input end 141 of the comparison circuit 140 is compared to be greater than the voltage of the second input end 142 of the comparison circuit 140 to trigger circuit protection.

[0040] Exemplarily, the voltage detection circuit 110 includes at least a voltage regulator D1, and the voltage regulator D1 includes a preset voltage range, and the minimum value of the preset voltage range is the undervoltage protection voltage U LVP The maximum value of the preset voltage range is the overvoltage protection voltage U OVP When the voltage Uin of the voltage port 111 to be detected is greater than the undervoltage protection voltage U LVP When the voltage Uin of the voltage port 111 to be detected is less than the undervoltage protection voltage U LVP When , the voltage regulator tube D1 is disconnected.

[0041] Exemplarily, the voltage detection circuit 110 also includes a voltage divider circuit, which includes at least two voltage divider resistors connected in series, the first output terminal 112 of the voltage detection circuit is arranged between the at least two resistors, the voltage regulator D1 is connected in parallel with one of the at least two voltage divider resistors, and the second output terminal 113 of the voltage detection circuit is used to output the divided voltage.

[0042] In one embodiment, Figure 1 As shown, the voltage detection circuit 110 includes a voltage divider circuit, which includes a first resistor R1, a second resistor R2 and a third resistor R3 connected in series, and a first output terminal 112 of the voltage detection circuit is set between the first resistor R1 and the second resistor R2. The voltage regulator D1 includes but is not limited to a diode, and the voltage regulator D1 is connected in series with the fourth resistor R4 and then connected in parallel with the third resistor R3, and the second output terminal 113 of the voltage detection circuit is set between the voltage regulator D1 and the fourth resistor R4.

[0043] In one embodiment, Figure 1 As shown, the voltage of the voltage regulator D1 is the divided voltage of the third resistor R3. LVPWhen the on-state voltage of the Zener diode D1 is LVP / (R1+R2+R3)×R3.

[0044] In one embodiment, when the voltage Uin of the voltage port 111 to be detected is less than the undervoltage protection voltage U LVP (Uin<U LVP ), the voltage regulator D1 is disconnected (ie, not conducting), and at this time, the first output terminal 112 of the voltage detection circuit 110 outputs the first detection voltage U to the comparison circuit 140. A , the second output terminal 113 of the voltage detection circuit 110 does not output voltage to the voltage conversion circuit 120. When the voltage Uin of the voltage port 111 to be detected is greater than or equal to the undervoltage protection voltage U LVP And less than or equal to the overvoltage protection voltage U OVP (U LVP ≤Uin≤U OVP ), the voltage regulator D1 is turned on, and the first output terminal 112 of the voltage detection circuit 110 outputs the first detection voltage U to the comparison circuit 140. A The second output terminal 113 of the voltage detection circuit 110 outputs the second detection voltage U to the voltage conversion circuit 120 B When the voltage Uin of the voltage port 111 to be detected is greater than the overvoltage protection voltage U OVP (Uin>U OVP ), the voltage regulator D1 is turned on. At this time, the first output terminal 112 of the voltage detection circuit 110 outputs the first detection voltage U to the comparison circuit 140. A The second output terminal 113 of the voltage detection circuit 110 outputs the second detection voltage U to the voltage conversion circuit 120 B .

[0045] Exemplarily, based on whether the voltage detection circuit outputs voltage to the voltage conversion circuit, the voltage conversion circuit selectively outputs a high level or a low level. Further, the voltage conversion circuit outputs the high level to the first input terminal 141 of the comparison circuit.

[0046] In one embodiment, the voltage conversion circuit 120 includes at least a transistor V1. When the second output terminal 113 of the voltage detection circuit 110 outputs a voltage to the voltage conversion circuit 120, when the transistor V1 is turned on, the voltage conversion circuit 120 outputs a low level; when the second output terminal 113 of the voltage detection circuit 110 does not output a voltage to the voltage conversion circuit 120, the transistor V1 is turned off, and the voltage conversion circuit 120 outputs a high level.

[0047] Exemplarily, the transistor includes two input terminals and one output terminal, the two input terminals of the transistor are respectively connected to the second output terminal 113 of the voltage detection circuit 110 and the voltage terminal Vcc, the output terminal of the transistor is grounded, and the output terminal of the voltage conversion circuit 120 is arranged between the transistor and the voltage terminal Vcc.

[0048] In one embodiment, the transistor is a triode, the base of the triode V1 is electrically connected to the second output terminal 113 of the voltage detection circuit 110, the collector of the triode V1 is electrically connected to the voltage terminal Vcc, the emitter of the triode V1 is grounded, and the output terminal of the voltage conversion circuit 120 is arranged between the triode V1 and the voltage terminal Vcc. Specifically, the base (B pole) of the triode V1 is electrically connected to the second output terminal 113 of the voltage detection circuit 110 via the fifth resistor R5, the collector (C pole) of the triode V1 is electrically connected to the voltage terminal Vcc via the sixth resistor R6, the emitter (E pole) of the triode V1 is grounded, and the output terminal of the voltage conversion circuit 120 is arranged between the triode V1 and the sixth resistor R6.

[0049] In one embodiment, when the voltage regulator D1 is turned on, the transistor is turned on, the voltage terminal Vcc is connected to the ground through the sixth resistor R6 and the transistor, and the voltage U at the output terminal of the voltage conversion circuit 120 is C When the voltage regulator D1 is disconnected (ie, not conducting), the transistor is turned off (ie, not conducting), and the voltage terminal Vcc is directly electrically connected to the output terminal of the voltage conversion circuit 120 via the sixth resistor R6. The voltage U at the output terminal of the voltage conversion circuit 120 is C is high level, at this time U C The voltage value is equal to the voltage value of the voltage terminal Vcc.

[0050] Exemplarily, the voltage at the first input terminal 141 of the comparison circuit 140 is the voltage U of the first output terminal 112 of the voltage detection circuit 110. A Or the voltage U at the output end of the voltage conversion circuit 120 C .

[0051] In one embodiment, the first output terminal 112 of the voltage detection circuit 110 is electrically connected to the first input terminal 141 of the comparison circuit 140 via a diode D2, and the second output terminal 113 of the voltage detection circuit 110 is also electrically connected to the first input terminal 141 of the comparison circuit 140 via a diode D3, wherein the diode D2 and the diode D3 are both used to prevent backflow.

[0052] In one embodiment, the first input terminal 141 of the comparison circuit 140 is used as the in-phase terminal to obtain the voltage U of the first output terminal 112 of the voltage detection circuit 110. AOr the voltage U at the output end of the voltage conversion circuit 120 C The first input terminal 141 of the comparison circuit 140 receives the voltage U of the first output terminal 112 of the voltage detection circuit 110. A The voltage U at the output end of the voltage conversion circuit 120 C The higher voltage is used as the input, that is, when U A >U C When U A As the input of the first input terminal 141 of the comparison circuit 140, when U A <U C When U C As the input of the first input terminal 141 of the comparison circuit 140; or, the first input terminal 141 of the comparison circuit 140 is the voltage U of the first output terminal 112 of the voltage detection circuit 110 A The voltage U at the output end of the voltage conversion circuit 120 C The lower voltage is used as the input, that is, when U A >U C When U C As the input of the first input terminal 141 of the comparison circuit 140, when U A <U C When U A The application does not limit the input of the first input terminal 141 of the comparison circuit 140 .

[0053] In one embodiment, the first input terminal 141 of the comparison circuit 140 is connected to the voltage U of the first output terminal 112 of the voltage detection circuit 110. A The voltage U at the output end of the voltage conversion circuit 120 C As an example, when the voltage conversion circuit 120 outputs a low level, the voltage of the first input terminal 141 of the comparison circuit 140 is the voltage U of the first output terminal 112 of the voltage detection circuit 110. A When the voltage at the output end of the voltage conversion circuit 120 is at a high level, the voltage at the first input end 141 of the comparison circuit 140 is the voltage U at the output end of the voltage conversion circuit C .

[0054] Exemplarily, comparing the voltage of the first input terminal 141 of the comparison circuit 140 to be greater than the voltage of the second input terminal 142 of the comparison circuit 140 to trigger circuit protection includes: when the voltage of the first input terminal 141 of the comparison circuit 140 is greater than the voltage of the second input terminal 142 of the comparison circuit 140, triggering the protection circuit; or, when the voltage of the first input terminal 141 of the comparison circuit 140 is less than the voltage of the second input terminal 142 of the comparison circuit 140, triggering the protection circuit, and the present application does not impose any restrictions on this.

[0055] Exemplarily, the comparison circuit 140 includes at least a comparator U2 and an output controller V2. Based on comparing the voltage of the first input terminal 141 of the comparison circuit 140 with the voltage of the second input terminal 142 of the comparison circuit 140, the comparator U2 outputs a high level or a low level; based on the level output by the comparator U2, the output controller V2 is turned on or off; when the output controller V2 is turned on, circuit protection is triggered; when the output controller V2 is turned off, circuit protection is not triggered.

[0056] In one embodiment, when the voltage of the first input terminal 141 of the comparison circuit 140 is greater than the voltage of the second input terminal 142 of the comparison circuit 140, the comparator U2 outputs a high level; or, when the voltage of the first input terminal 141 of the comparison circuit 140 is less than the voltage of the second input terminal 142 of the comparison circuit 140, the comparator U2 outputs a high level, and the present application does not impose any restrictions on this.

[0057] In one embodiment, when the comparator U2 outputs a high level, the output controller V2 is turned on; or, when the comparator U2 outputs a low level, the output controller V2 is turned on, and the present application does not impose any limitation on this.

[0058] In one embodiment, when the voltage at the first input terminal 141 of the comparison circuit 140 is greater than the voltage at the second input terminal 142 of the comparison circuit 140, the comparator U2 outputs a high level, the output controller V2 is turned on, and the circuit protection is triggered; when the voltage at the first input terminal 141 of the comparison circuit 140 is less than the voltage at the second input terminal 142 of the comparison circuit 140, the comparator U2 outputs a low level, the output controller V2 is turned off, and the circuit protection is not triggered. The output terminal of the reference voltage circuit 130 provides a stable reference voltage to the second input terminal 142 of the comparison circuit 140.

[0059] Exemplarily, the output end of the reference voltage circuit 130 provides a stable reference voltage to the second input end 142 of the comparison circuit 140, wherein: the reference voltage circuit 130 includes a three-terminal regulator U1 and three resistors connected in series, the first lead terminal and the second lead terminal of the three-terminal regulator are electrically connected to adjacent resistors respectively, and the third lead terminal of the three-terminal regulator is grounded.

[0060] In one embodiment, Figure 1 As shown, the reference voltage circuit 130 includes a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9 connected in series, and the reference voltage circuit 130 also includes a three-terminal voltage regulator U1, a first lead terminal of the three-terminal voltage regulator U1 is electrically connected between the seventh resistor R7 and the eighth resistor R8, a second lead terminal of the three-terminal voltage regulator U1 is electrically connected between the eighth resistor R8 and the ninth resistor R9, and a third lead terminal of the three-terminal voltage regulator U1 is grounded. The input terminal of the reference voltage circuit 130 is electrically connected to the voltage terminal Vcc, the output terminal of the reference voltage circuit 130 is set between the seventh resistor R7 and the eighth resistor R8, and the output terminal of the reference voltage circuit 130 is electrically connected to the second input terminal 142 of the comparison circuit 140. The voltage V at the output terminal of the reference voltage circuit 130 is ref is the reference voltage. ref =U OVP / (R1+R2+R3'), R3'=R3 / / R4. It should be noted that the electrical connection method of the reference voltage circuit 130 is only exemplary, and any circuit that can provide a stable reference voltage for the comparison circuit 140 is applicable to the present application.

[0061] In one embodiment, Figure 1 As shown, the positive electrode of the comparator U2 is used as the first input terminal 141 of the comparison circuit 140, the negative electrode of the comparator U2 is used as the second input terminal 142 of the comparison circuit 140, and the positive electrode of the comparator U2 obtains the voltage U of the first output terminal 112 of the voltage detection circuit 110. A The voltage U at the output end of the voltage conversion circuit 120 C The higher voltage value is used as input, and the negative electrode of the comparator U2 obtains the reference voltage V at the output end of the reference voltage circuit 130. ref As input, comparator U2 takes the voltage (U A or U C ) and the reference voltage V obtained at the negative electrode ref When the voltage of the positive electrode is greater than the voltage of the negative electrode, the voltage U output by the comparator U2 is D When the positive voltage is lower than the negative voltage, the comparator U2 outputs a voltage U D is low level; or, when the voltage of the positive electrode is less than the voltage of the negative electrode, the voltage U output by the comparator U2 isD When the positive voltage is greater than the negative voltage, the comparator U2 outputs a voltage U D The comparator U2 may also be an operational amplifier, which is not limited in this application.

[0062] In one embodiment, the output controller V2 obtains the voltage U output by the comparator U2. D , when U D When it is high level, the drive output controller V2 works, or when U D When the output controller V2 is at a low level, the drive output controller V2 works. When the drive output controller V2 works, the control signal is pulled low, triggering the circuit protection. When the drive output controller V2 does not work, the control signal will not be pulled low, and the circuit protection will not be triggered. The output controller V2 can be a triode, a MOSFET, a thyristor, etc., and this application does not limit this.

[0063] In one embodiment, the working process of the over-voltage and under-voltage protection circuit is as follows: when the voltage to be detected Uin is less than the under-voltage protection voltage U LVP (Uin<U LVP ), the first output terminal 112 of the voltage detection circuit 110 outputs the first detection voltage U to the comparison circuit 140. A Less than the reference voltage V ref The voltage Uin (also referred to as the voltage Uin) at the voltage terminal 111 to be detected is divided by the first resistor R1, the second resistor R2 and the third resistor R3. The voltage divided by the third resistor R3 is not enough to turn on the voltage regulator D1. The voltage regulator D1 is disconnected (i.e., not conducting), the transistor V1 is turned off (i.e., not conducting), and the voltage Uin at the output terminal of the voltage conversion circuit 120 is C is high level, U C Greater than the reference voltage V ref , the voltage U output by comparator U2 D When the voltage to be detected Uin is greater than or equal to the undervoltage protection voltage U LVP And less than or equal to the overvoltage protection voltage U OVP (U LVP ≤Uin≤U OVP ), the first output terminal 112 of the voltage detection circuit 110 outputs the first detection voltage U to the comparison circuit 140. A Less than the reference voltage V refThe voltage Uin (also referred to as the voltage Uin to be detected) of the voltage port 111 to be detected is divided by the first resistor R1, the second resistor R2 and the third resistor R3. The voltage divided by the third resistor R3 can reach the conduction voltage of the voltage regulator D1. The voltage regulator D1 is turned on, the transistor V1 is turned on, and the voltage Uin at the output end of the voltage conversion circuit 120 is C is low level, U C Less than the reference voltage V ref , the voltage U output by comparator U2 D When the voltage to be detected Uin is greater than the overvoltage protection voltage U OVP (Uin>U OVP ), the first output terminal 112 of the voltage detection circuit 110 outputs the first detection voltage U to the comparison circuit 140. A Greater than the reference voltage V ref The voltage Uin (also referred to as the voltage Uin to be detected) of the voltage port 111 to be detected is divided by the first resistor R1, the second resistor R2 and the third resistor R3. The voltage divided by the third resistor R3 can reach the conduction voltage of the voltage regulator D1. The voltage regulator D1 is turned on, the transistor V1 is turned on, and the voltage Uin at the output end of the voltage conversion circuit 120 is C is low level, U A As the voltage of the first input terminal 141 of the comparison circuit 140, U A Greater than V ref , so the comparator U2 outputs a voltage U D It is at a high level, driving the output controller V2 to work, and the control signal is pulled low, triggering the circuit overvoltage protection.

[0064] The utility model also provides a vehicle-mounted power supply, which comprises the over-voltage and under-voltage protection circuit mentioned above.

[0065] The utility model also provides a vehicle, and the vehicle comprises the above-mentioned on-vehicle power supply.

[0066] According to the over- and under-voltage protection circuit, vehicle-mounted power supply and vehicle provided by the utility model, the first output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit, the second output end of the voltage detection circuit is also electrically connected to the first input end of the comparison circuit via the voltage conversion circuit, and the output end of the reference voltage circuit is electrically connected to the second input end of the comparison circuit, and then the voltage at the first input end of the comparison circuit is compared with the voltage at the second input end of the comparison circuit to determine whether to trigger circuit protection. The over- and under-voltage protection circuit only uses one comparator to complete the circuit protection of overvoltage and undervoltage, reduces the number of circuit components, simplifies the circuit design, and is conducive to the integration of circuits and the miniaturization of vehicle-mounted power supplies.

[0067] The utility model has been described through the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the utility model to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the utility model is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the utility model, and these variations and modifications all fall within the scope of the protection claimed by the utility model. The protection scope of the utility model is defined by the attached claims and their equivalents.

Claims

1. An over-voltage and under-voltage protection circuit, characterized in that: It includes a voltage detection circuit, a voltage conversion circuit, a reference voltage circuit and a comparison circuit. The input end of the voltage detection circuit is electrically connected to a voltage port to be detected, the first output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit, the second output end of the voltage detection circuit is electrically connected to the first input end of the comparison circuit via the voltage conversion circuit, the output end of the reference voltage circuit is electrically connected to the second input end of the comparison circuit, and the voltage at the first input end of the comparison circuit is compared with the voltage at the second input end of the comparison circuit to trigger circuit protection.

2. The over-voltage and under-voltage protection circuit according to claim 1, characterized in that: The voltage conversion circuit selectively outputs a high level or a low level based on whether the voltage detection circuit outputs a voltage to the voltage conversion circuit.

3. The over-voltage and under-voltage protection circuit according to claim 1, characterized in that: The voltage detection circuit at least includes a Zener diode. When the voltage value of the voltage port to be detected is greater than the undervoltage protection voltage, the Zener diode is turned on. When the voltage value of the voltage port to be detected is less than the undervoltage protection voltage, the Zener diode is not turned on.

4. The over-voltage and under-voltage protection circuit according to claim 3, characterized in that: The voltage detection circuit also includes a voltage divider circuit, which includes at least two voltage divider resistors connected in series. The first output end of the voltage detection circuit is arranged between the at least two resistors. The voltage regulator is connected in parallel with one of the at least two voltage divider resistors. The second output end of the voltage detection circuit is used to output the divided voltage.

5. The over-voltage and under-voltage protection circuit according to claim 2, characterized in that: The voltage conversion circuit comprises at least a transistor: When the second output terminal of the voltage detection circuit outputs a voltage to the voltage conversion circuit, the transistor is turned on and the voltage conversion circuit outputs a low level; When the second output terminal of the voltage detection circuit does not output a voltage to the voltage conversion circuit, the transistor is turned off, and the voltage conversion circuit outputs a high level.

6. The over-voltage and under-voltage protection circuit according to claim 5, characterized in that: The transistor includes two input terminals and one output terminal. The two input terminals of the transistor are respectively connected to the second output terminal and the voltage terminal of the voltage detection circuit. The output terminal of the transistor is grounded. The output terminal of the voltage conversion circuit is arranged between the transistor and the voltage terminal.

7. The over-voltage and under-voltage protection circuit according to claim 1, characterized in that: The voltage at the first input terminal of the comparison circuit is the voltage at the first output terminal of the voltage detection circuit or the voltage at the output terminal of the voltage conversion circuit.

8. The over-voltage and under-voltage protection circuit according to claim 7, characterized in that: The comparison circuit at least includes a comparator and an output controller. Based on comparing the voltage of the first input terminal of the comparison circuit with the voltage of the second input terminal of the comparison circuit, the comparator outputs a high level or a low level; Based on the level of the comparator output, the output controller is turned on or off; When the output controller is turned on, circuit protection is triggered; When the output controller is turned off, the circuit protection is not triggered.

9. The over-voltage and under-voltage protection circuit according to claim 1, characterized in that: The output terminal of the reference voltage circuit provides a stable reference voltage to the second input terminal of the comparison circuit, wherein: The reference voltage circuit includes a three-terminal regulator and three resistors connected in series, wherein a first lead terminal and a second lead terminal of the three-terminal regulator are electrically connected to adjacent resistors respectively, and a third lead terminal of the three-terminal regulator is grounded.

10. A vehicle-mounted power supply, characterized in that: The invention comprises the over-voltage and under-voltage protection circuit according to any one of claims 1 to 9.

11. A vehicle, characterized in that: Includes the vehicle-mounted power supply as claimed in claim 10.

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