CN216959294U - Overvoltage protection circuit and electronic equipment - Google Patents
Overvoltage protection circuit and electronic equipment Download PDFInfo
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- CN216959294U CN216959294U CN202123390511.3U CN202123390511U CN216959294U CN 216959294 U CN216959294 U CN 216959294U CN 202123390511 U CN202123390511 U CN 202123390511U CN 216959294 U CN216959294 U CN 216959294U
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Abstract
The application belongs to the technical field of circuit protection, provides an overvoltage crowbar and electronic equipment, wherein, overvoltage crowbar includes: the overvoltage protection circuit is used for generating an overvoltage protection signal when the input voltage of the power input interface is larger than a preset threshold voltage, the overvoltage bleeder circuit is used for generating a turn-off signal according to the overvoltage protection signal, the enable drive circuit is used for outputting the enable signal to the enable end of the power supply circuit and outputting the power supply voltage to the power input end of the power supply circuit, the power supply circuit is used for carrying out voltage conversion on the power supply voltage so as to output the working voltage required by the work of the electronic equipment and stopping outputting the working voltage when the turn-off signal is received, and the overvoltage protection circuit can solve the problem that the power supply of the existing electronic equipment is easy to generate large voltage after being electrified so as to damage the electronic equipment.
Description
Technical Field
The application belongs to the technical field of circuit protection, and particularly relates to an overvoltage protection circuit and electronic equipment.
Background
Automobiles have become an increasing household choice. In the use process of the automobile, due to the fact that the automobile is not used for a long time or the vehicle-mounted electric appliance is not timely turned off after flameout, the electric quantity of an automobile storage battery is insufficient, even the situation of undervoltage occurs, and therefore the problem that the automobile cannot be normally started is caused. The battery maintenance device is used for charging the automobile storage battery after voltage conversion is carried out on direct current input by the direct current power supply, so that the electric quantity of the storage battery is supplemented.
However, the conventional battery maintainer has the problem that after a power supply is powered on, a large voltage is easily generated, and then the battery maintainer is damaged. Similar electronic equipment also has a corresponding problem that when the power supply is powered on, the power supply input interface generates large voltage to damage the electronic equipment.
SUMMERY OF THE UTILITY MODEL
In order to solve the technical problem, an embodiment of the application provides an overvoltage protection circuit and an electronic device, which can solve the problem that the existing electronic device is easy to generate large voltage after a power supply is powered on, and further damages the electronic device.
A first aspect of an embodiment of the present application provides an overvoltage protection circuit, which is applied to an electronic device, where the overvoltage protection circuit includes: 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.
In one embodiment, the over-voltage detection circuit includes 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.
In one embodiment, the enable driving circuit includes: a first voltage division unit and a second voltage division 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.
In one embodiment, the enable driving 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.
In one embodiment, the first voltage division unit 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.
In one embodiment, the over-voltage 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.
In one embodiment, the power supply circuit includes: 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.
In one embodiment, the power supply circuit further includes: 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.
A second aspect of an embodiment of the present application provides an electronic device, including: a power input interface and an overvoltage protection circuit as described in any one of the above; the power input interface is connected with the first end of the overvoltage protection circuit.
In one embodiment, 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.
The embodiment of the application provides an overvoltage crowbar and electronic equipment, wherein, overvoltage crowbar includes: the overvoltage protection circuit comprises an overvoltage detection circuit, an overvoltage discharge circuit, an enable driving circuit and a power supply circuit; wherein, the overvoltage detection circuit is used for generating an overvoltage protection signal when the input voltage of the power input interface is larger than a preset threshold voltage, the overvoltage bleeder circuit is used for receiving the overvoltage protection signal, and generates a turn-off signal to the enable terminal of the power supply circuit according to the overvoltage protection signal, the enable driving circuit is used for outputting an enable signal to the enable terminal of the power supply circuit according to the input voltage of the power input interface, and outputting the power supply voltage to a power input terminal of a power supply circuit, the power supply circuit being configured to, upon receiving an enable signal, converting the power supply voltage to output a working voltage required by the electronic device, and stopping outputting the working voltage when receiving the turn-off signal, the overvoltage protection circuit can solve the problem that the conventional electronic equipment is easy to generate large voltage after a power supply is powered on, so that the electronic equipment is damaged.
Drawings
Fig. 1 is a schematic structural diagram of an overvoltage protection circuit provided in an embodiment of the present application;
FIG. 2 is a schematic diagram showing an embodiment of an overvoltage protection circuit according to the present application;
fig. 3 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be 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 be indirectly connected to the other element.
It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, refer to an orientation or positional relationship illustrated in the drawings for convenience in describing the present application and to simplify description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means one or more unless specifically limited otherwise.
With the improvement of living standard of people and the rapid development of automobile industry, users use automobiles more frequently, which also puts higher requirements on the charging technology of automobile storage batteries. Most of storage batteries used for automobiles are charged through direct charging, the charging speed of the storage batteries can be greatly improved through the direct charging, but certain potential safety hazards also exist at the same time, for example, when the power supply input side circuit cannot supply power, the power supply output side circuit can generate large voltage for the power supply input side circuit, thereby possibly generating large voltage impact on the battery maintenance device, finally possibly causing the damage of the battery maintenance device, even generating fire, similar electronic equipment can also have corresponding problems, namely, when the power supply is powered on, the power supply input interface generates large voltage and further damages the electronic equipment.
In order to solve the above technical problem, an embodiment of the present application provides an overvoltage protection circuit applied to an electronic device, and referring to fig. 1, the overvoltage protection circuit includes: an overvoltage detection circuit 20, an overvoltage relief circuit 40, an enable driver circuit 30, and a power supply circuit 50.
Specifically, a detection end of the overvoltage detection circuit 20 is connected to the power input interface 10 of the electronic device, the overvoltage detection circuit 20 is configured to generate an overvoltage protection signal when an input voltage of the power input interface 10 is greater than a preset threshold voltage, an input end of the overvoltage bleeder circuit 40 is connected to an output end of the overvoltage detection circuit 20, an output end of the overvoltage bleeder circuit 40 is connected to an enable end of the power supply circuit 50, a ground end of the overvoltage bleeder circuit 40 is grounded, and the overvoltage bleeder circuit 40 is configured to bleed the input voltage when receiving the overvoltage protection signal and generate a turn-off signal to the enable end of the power supply circuit 50 according to the overvoltage protection signal; the input end of the enable driving circuit 30 is connected to the power input interface 10, the first output end of the enable driving circuit 30 is connected to the power input end of the power supply circuit 50, the second output end of the enable driving circuit 30 is connected to the enable end of the power supply circuit 50, the enable driving circuit 30 is configured to output an enable signal to the enable end of the power supply circuit 50 according to the input voltage of the power input interface 10 and output a power supply voltage to the power input end of the power supply circuit 50, and the power supply circuit 50 is configured to perform voltage conversion on the power supply voltage to output a working voltage required by the electronic device when receiving the enable signal, and stop outputting the working voltage when receiving the shutdown signal.
In this embodiment, the overvoltage detection circuit 20 may compare the input voltage of the power input interface 10 with a preset threshold voltage, and generate the 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 indicates that a large voltage occurs in the circuit, and if the large voltage enters the electronic device, the electronic device may be damaged, and at this time, the overvoltage detection circuit 20 generates an overvoltage protection signal.
In the embodiment, the overvoltage discharging 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 working voltage when receiving the shutdown signal. Specifically, after the overvoltage relief circuit 40 receives the overvoltage protection signal, it is described that overvoltage occurs in the circuit, and the overvoltage relief circuit 40 generates a turn-off signal at this time, so that the power supply circuit 50 stops working and stops outputting working voltage, the electronic equipment can be effectively protected, the electronic equipment is prevented from being damaged, and the problem that the existing electronic equipment power supply is easily subjected to large voltage generation after being electrified, and then the electronic equipment is damaged is solved.
In the embodiment, the enable driving circuit 30 is configured to supply power to the power supply circuit 50, and output an enable signal to an enable terminal of the power supply circuit 50 according to the input voltage of the power input interface 10 to control the power supply circuit 50 to output the operating voltage. Specifically, the input end of the enable driving circuit 30 is connected to the power input interface 10, the first output end of the enable driving circuit 30 is connected to the power input end VIN of the power supply circuit 50, the second output end of the enable driving circuit 30 is connected to the enable end EN of the power supply circuit 50, and the enable driving circuit 30 is configured to output an enable signal to the enable end EN of the power supply circuit 50 according to the input voltage of the power input interface 10 and output a supply voltage to the power input end VIN of the power supply circuit 50. The power supply circuit 50 is configured to perform voltage conversion on the power supply voltage to output a working voltage required by the operation of the electronic device when receiving the enable signal, and stop outputting the working voltage when receiving the turn-off signal, so as to disconnect the electronic device when the input voltage has overvoltage, thereby protecting the electronic device and other related devices.
In one embodiment, referring to fig. 2, the over-voltage detection circuit 20 includes a first voltage regulator D1.
Specifically, the negative electrode of the first voltage regulator tube D1 is connected to the power input interface 10, and the positive electrode of the first voltage regulator tube D1 is connected to the overvoltage bleeder 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 tube D1 is turned on, so as to generate an overvoltage protection signal, and after receiving the overvoltage protection signal, the overvoltage bleeder circuit 40 generates a turn-off signal according to the overvoltage protection signal, so as to control the power supply circuit 50 to stop outputting the working voltage, thereby solving the problem that the existing electronic equipment is easy to generate a large voltage after the power supply is powered on, and further damages the electronic equipment.
In one embodiment, the first regulator tube D1 has forward conduction, reverse cut-off and one-way conduction, if the reverse voltage on the first regulator tube D1 exceeds the bearing capacity of the first regulator tube D1, that is, when the reverse voltage exceeds a preset threshold voltage, the first regulator tube D1 will be broken down, although the first regulator tube D1 is in a breakdown state, the first regulator tube D1 will not be damaged by a large current, and the repeatability of the phenomenon is good, as long as the first regulator tube D1 is in the breakdown state, although the electricity flowing through the tube varies greatly, the voltage at the two ends of the tube changes extremely little to play a role of voltage stabilization, and the first regulator tube D1 can be arranged to find an overvoltage phenomenon in the circuit in time to prevent the electronic equipment from being damaged.
In one embodiment, referring to fig. 2, the enable driving circuit 30 includes: a first pressure dividing unit 31 and a second pressure dividing unit 32.
Specifically, a first end of the first voltage dividing unit 31 is connected to the power input interface 10, a second end of the first voltage dividing unit 31 is connected to a first end of the second voltage dividing unit 32, a first end of the second voltage dividing unit 32 is further connected to a first output end of the enable driving circuit 30, a second end of the second voltage dividing unit 32 is connected to a second output end of the enable driving circuit 30, and the first voltage dividing unit 31 and the second voltage dividing unit 32 are configured to perform voltage dividing processing on a voltage signal input by the power input interface 10 to form a corresponding voltage at a power input end and an enable end of the power supply circuit 50.
In this embodiment, when the power input interface 10 is connected to an external power source, the first voltage dividing unit 31 and the second voltage dividing unit 32 divide the voltage signal input by the power input interface 10 to generate a voltage suitable for the power supply circuit 50, so as to supply power to the power supply circuit 50, so that the power supply circuit 50 can operate 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, output a supply voltage to the power input terminal of the power supply circuit 50, and start normal operation of the power supply circuit 50 to output a working voltage.
In one embodiment, referring to fig. 2, the enable driver circuit 30 further includes: a first filter circuit 33.
Specifically, a first end of the first filter circuit 33 is connected to a second end of the first voltage dividing unit 31, a second end of the first filter circuit 33 is grounded, and the first filter circuit 33 is configured to perform voltage stabilizing filtering processing on a voltage at a power input end of the power supply circuit 50. The first filter circuit 33 is provided to reduce the ac component in the voltage at the power supply interface of the power supply circuit 50, and to retain the dc component, so that the ripple factor of the output voltage is reduced and the waveform becomes smoother.
In one embodiment, referring to fig. 2, the first voltage division unit 31 includes a first resistor R1 and a third resistor R3; the second voltage dividing unit 32 includes a second resistor R2.
Specifically, a first end of the first resistor R1 is connected to the power input interface 10, a 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 to the first resistor R1, a first end of the second resistor R2 is connected to the power input end of the power supply circuit 50, and a 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 source, the first resistor R1, the second resistor R2, and the third resistor R3 divide a voltage signal input by the power input interface 10 to generate a voltage suitable for the power supply circuit 50, so as to supply power to the power supply circuit 50, so that the power supply circuit 50 can operate normally. The third resistor R3 is connected in parallel with the first resistor R1, and the third resistor R3 is connected in parallel with the first resistor R1, and it functions that when the first resistor R1 fails, the third resistor R3 is connected in series with the second resistor R2 and is responsible for dividing the voltage signal input by the power input interface 10, or when the third resistor R3 fails, the first resistor R1 is connected in series with the second resistor R2 and is responsible for dividing the voltage signal input by the power input interface 10. In other embodiments, the first voltage dividing unit 31 may also be configured according to voltage dividing requirements, for example, only one resistor is provided, or a plurality of resistors are connected in series and parallel.
In one embodiment, referring to 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, the second end of the first capacitor C1, the second end of the second capacitor C2, and the second end of the third capacitor C3 are all grounded, and the first capacitor C1, the second capacitor C2, and the third capacitor C3 are used for performing voltage stabilizing and filtering processing on the voltage at the input end of the power supply circuit 50.
In this embodiment, when the power input interface 10 is connected to an external power source, the first capacitor C1, the second capacitor C2, and the third capacitor C3 perform voltage stabilization filtering processing 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, retain the dc component thereof, reduce the ripple coefficient of the output voltage, and make the waveform smoother, so that the power supply circuit 50 can normally operate.
In one embodiment, referring to fig. 2, the overvoltage relief circuit 40 includes: a fourth resistor R4, a fifth resistor R5, a fourth capacitor C4 and a first switch tube Q1.
Specifically, a first end of the fourth resistor R4 is connected to the output end of the overvoltage detection circuit 20, a second end of the fourth resistor R4 is connected to 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 to the enable end of the power supply circuit 50.
In this embodiment, the fourth resistor R4 and the fifth resistor R5 are used for dividing the voltage of the overvoltage protection signal, the on and off voltage values of different switch units are different, and by arranging the fourth resistor R4 and the fifth resistor R5, the voltage of the overvoltage protection signal can be subjected to voltage division processing to ensure that the voltage of the overvoltage protection signal meets the requirements of the switch-on and switch-off of the switch unit, so that the first switch tube Q1 can accurately receive the overvoltage protection signal, the first switch tube Q1 is used for generating a turn-off signal according to the overvoltage protection signal to control whether the power supply circuit 50 outputs the working voltage, further, when overvoltage occurs in the circuit, the first switching tube Q1 generates a turn-off signal, and the power supply circuit 50 does not output a working voltage, so that the problem that the conventional electronic device power supply is easily subjected to large voltage generation after being powered on, and further the electronic device is damaged is solved.
In this embodiment, the fourth capacitor C4 is used to regulate the voltage of the control terminal of the first switch transistor Q1, so as to ensure that the first switch transistor Q1 can be stably in an off or on state.
In one embodiment, referring to fig. 2, the power supply circuit 50 includes: a voltage stabilizing unit 51 and a second filtering unit 52.
Specifically, the power input terminal of the voltage stabilizing unit 51 is connected to the output terminal of the enable driving circuit 30, the enable terminal of the voltage stabilizing unit 51 is connected to the first output terminal of the enable driving circuit 30, the enable terminal of the voltage stabilizing unit is connected to the second output terminal of the enable driving circuit 30, the enable terminal of the voltage stabilizing unit 51 is further connected to the output terminal of the overvoltage bleeder circuit 40, the output terminal of the voltage stabilizing unit 51 is connected to the first terminal of the second filtering unit 52, and the second terminal of the second filtering unit 52 is grounded.
In this embodiment, the voltage stabilizing unit 51 is configured to output the working voltage according to the enable signal and stop outputting the working voltage according to the shutdown signal, and the second filtering unit 52 is configured to perform filtering processing on the working voltage output by the voltage stabilizing unit 51.
In one embodiment, as shown with reference to fig. 2, the power supply circuit 50 further includes: a noise bypass unit 53.
Specifically, a first end of the noise bypass unit 53 is connected to the noise bypass end BP of the voltage stabilizing unit 51, a second end of the noise bypass unit 53 is grounded, and the noise bypass unit 53 is configured to reduce the output noise of the voltage stabilizing unit 51.
In one embodiment, referring to 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, the drain of the NMOS transistor corresponds to the second terminal of the first switch transistor Q1 and is connected to the power supply circuit 50, and the source of the NMOS transistor corresponds to the first terminal of the first switch transistor Q1 and is grounded. The overvoltage protection circuit comprises a power input interface 10, wherein an overvoltage protection signal is generated when the input voltage of the power input interface is greater than a preset threshold voltage, the overvoltage protection signal is a high level signal, the overvoltage protection signal is sent to a control end of an NMOS (N-channel metal oxide semiconductor) tube through a fourth resistor R4 and a fifth resistor R5, the NMOS tube is conducted, the level of an enable end EN of a power supply circuit 50 is pulled down to be a low level, namely, a low level turn-off signal is formed, the power supply circuit 50 stops outputting working voltage, and the problem that the existing electronic equipment is easy to generate large voltage after the power supply is powered on and further damages the electronic equipment is solved.
In one embodiment, the over-voltage detection circuit 20 and the enable driving circuit 30 are connected to the power input interface 10 of the electronic device via a signal line BUS +.
An embodiment of the present application further provides an electronic device, as shown in fig. 3, including: a power input interface 10 and an overvoltage protection circuit as in any one of the above; wherein, the power input interface 10 is connected with a first end of the overvoltage protection circuit.
In one embodiment, as shown with reference to 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 operating power end of the voltage conversion circuit 60 is connected to the output end of the power supply circuit 50, 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 configured to convert the input voltage to generate the target output voltage to the power output interface 70.
In this embodiment, the voltage converting circuit 60 converts the operating voltage output by the overvoltage protection circuit and sends the converted operating voltage to the power output interface 70.
The electronic device can be a voltage conversion device and is used for converting voltage input by an external power supply and outputting the converted voltage to the target device for power supply. In one embodiment, the electronic device may be a battery maintainer. Taking the battery maintenance device as an example, when the input voltage of the power input interface 10 is greater than the preset threshold voltage, it is indicated that a large voltage occurs in the circuit, if the battery maintenance device is damaged when the battery is charged at this time, the overvoltage detection circuit 20 generates an overvoltage protection signal, after the overvoltage relief circuit 40 receives the overvoltage protection signal, a turn-off signal is generated according to the overvoltage protection signal, so as 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 working voltage and is in an inoperative state, i.e., the voltage output by the power input interface 10 is not converted, and a working voltage signal is not generated and sent to the power output interface 70.
The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
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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| CN202123390511.3U CN216959294U (en) | 2021-12-29 | 2021-12-29 | Overvoltage protection circuit and electronic equipment |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116566024A (en) * | 2023-07-11 | 2023-08-08 | 成都利普芯微电子有限公司 | Battery protection system and lithium battery protection chip |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116566024A (en) * | 2023-07-11 | 2023-08-08 | 成都利普芯微电子有限公司 | Battery protection system and lithium battery protection chip |
| CN116566024B (en) * | 2023-07-11 | 2023-09-29 | 成都利普芯微电子有限公司 | Battery protection system and lithium battery protection chip |
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