Power supply short circuit protection circuit and electronic equipment
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHUHAI OUSENSI TECH CO LTD
- Filing Date
- 2025-04-28
- Publication Date
- 2026-05-12
AI Technical Summary
Existing power protection measures such as fuse and efuse are inadequate in terms of response time, maintainability, and cost, and may cause damage to the battery and subsequent circuits after short circuit protection.
An interlocking structure composed of P-type and N-type field-effect transistors, combined with unidirectional conduction units and capacitive units, is used to achieve short-circuit protection and self-recovery after the fault is cleared.
实现了快速、可靠的短路保护，并在负载恢复正常后自动恢复供电，提高了电子设备的工作可靠性。
Smart Images
Figure CN224233330U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power protection technology, and in particular to a power short-circuit protection circuit and electronic equipment. Background Technology
[0002] With the development of technology, people are paying more and more attention to safe production. Many industries have begun to use sensors to remotely monitor product conditions, such as natural gas meters and hazardous gas monitoring. This requires that abnormalities in the sensors themselves should not cause product abnormalities, thereby ensuring production safety. Short-circuit protection in sensor equipment is an important function, used to prevent equipment damage, fire, or other dangerous situations caused by short circuits in the circuit. Common power protection measures include fuses and efuse. The working principle of a fuse is relatively simple: when the current exceeds its rated value, the fuse will melt and cut off the circuit. However, its melting response time is relatively slow, it is disposable, and its maintainability is poor. Compared to fuses, efuse is more complex in principle and more powerful in function. Its main features are fast response, resettable, programmable, and providing OCP / OVP protection. However, its cost is relatively high, and because it is resettable, when a short circuit occurs, it will disconnect the current path. After the current drops to its programmed value, the efuse will reopen the current path, putting it in a cycle of short circuit and open circuit, which is extremely harmful to the battery and downstream circuits. Utility Model Content
[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a power supply short-circuit protection circuit and electronic device, which has a simple circuit structure and can achieve short-circuit protection and self-recovery.
[0004] On one hand, this utility model embodiment provides a power supply short-circuit protection circuit, including:
[0005] The first field-effect transistor unit has an input terminal and an output terminal. The input terminal of the first field-effect transistor unit is used to connect to the input power supply, and the output terminal of the first field-effect transistor unit is used to connect to the load.
[0006] The second field-effect transistor unit has a polarity opposite to that of the first field-effect transistor unit. The input terminal of the second field-effect transistor unit is connected to the control terminal of the first field-effect transistor unit, and the output terminal of the second field-effect transistor unit is connected to the reference voltage terminal. The control terminal of the second field-effect transistor unit is connected to the output terminal of the first field-effect transistor unit.
[0007] The unidirectional conduction unit has its input terminal connected to the control terminal of the first field-effect transistor unit. The output terminal of the unidirectional conduction unit is connected to a capacitive unit and is connected to the reference voltage terminal through the capacitive unit. Both the input and output terminals of the unidirectional conduction unit are also connected to the input power supply.
[0008] According to some embodiments of the present invention, the first field-effect transistor unit adopts a P-type field-effect transistor.
[0009] According to some embodiments of the present invention, the second field-effect transistor unit adopts an N-type field-effect transistor.
[0010] According to some embodiments of the present invention, the control terminal of the second field-effect transistor unit is connected to a first current-limiting resistor, and is connected to the output terminal of the first field-effect transistor unit through the first current-limiting resistor.
[0011] According to some embodiments of this utility model, the unidirectional conduction unit is a diode.
[0012] According to some embodiments of the present invention, the input terminal of the unidirectional conduction unit is connected to a first current-limiting resistor, and is connected to the input power supply through the first current-limiting resistor.
[0013] According to some embodiments of the present invention, the output terminal of the unidirectional conduction unit is connected to a second current-limiting resistor, and is connected to the input power supply through the second current-limiting resistor.
[0014] According to some embodiments of this utility model, the capacitive unit is a single capacitor or a group of capacitors.
[0015] According to some embodiments of the present invention, the output terminal of the first field-effect transistor unit is connected to a capacitor filter unit.
[0016] On the other hand, this utility model embodiment provides an electronic device, characterized in that it includes the above-mentioned power supply short-circuit protection circuit.
[0017] The embodiments of this utility model have at least the following beneficial effects:
[0018] Under stable operating conditions, the first and second field-effect transistor units are turned on and form an interlocking structure. The unidirectional conduction unit and the capacitive unit maintain the stable operating state of the first and second field-effect transistor units. When a short-circuit fault occurs, the voltage at the control terminal of the second field-effect transistor unit drops, causing the second and first field-effect transistor units to turn off, thereby disconnecting the power supply to the load. When the load returns to normal, the first and second field-effect transistor units re-enter the stable operating state. In this way, short-circuit protection and self-recovery can be achieved through a simple circuit structure, which is beneficial to improving the reliability of electronic equipment.
[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0020] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0021] Figure 1 This is a schematic block diagram of the power protection circuit according to an embodiment of the present utility model;
[0022] Figure 2 This is a circuit diagram of the power protection circuit according to an embodiment of the present invention.
[0023] Figure label:
[0024] First field-effect transistor unit 100, second field-effect transistor unit 200, unidirectional conduction unit 300, capacitive unit 400. Detailed Implementation
[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0026] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first," "second," etc., are used in the description, they are only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features.
[0027] In the description of this utility model, unless otherwise explicitly defined, the terms "setting", "installation", "connection", etc. should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in combination with the specific content of the technical solution.
[0028] This embodiment discloses an electronic device, including a power supply short-circuit protection circuit. Please refer to... Figure 1The power supply short-circuit protection circuit includes a first field-effect transistor unit 100, a second field-effect transistor unit 200, and a unidirectional conduction unit 300. The first field-effect transistor unit 100 has an input terminal and an output terminal. The input terminal of the first field-effect transistor unit 100 is used to connect to the input power supply, and the output terminal of the first field-effect transistor unit 100 is used to connect to the load. The polarity of the second field-effect transistor unit 200 is opposite to that of the first field-effect transistor unit 100. The input terminal of the second field-effect transistor unit 200 is connected to the control terminal of the first field-effect transistor unit 100, and the output terminal of the unidirectional conduction unit 300 is connected to a capacitive unit 400 and connected to the reference voltage terminal through the capacitive unit 400. Both the input terminal and the output terminal of the unidirectional conduction unit 300 are also connected to the input power supply.
[0029] Under stable operating conditions, the first field-effect transistor unit 100 and the second field-effect transistor unit 200 are turned on and form an interlocking structure. The unidirectional conduction unit 300 and the capacitive unit 400 maintain the stable operating state of the first field-effect transistor unit 100 and the second field-effect transistor unit 200. When a short-circuit fault occurs, the voltage at the control terminal of the second field-effect transistor unit 200 drops, causing the second field-effect transistor unit 200 and the first field-effect transistor unit 100 to be turned off, thereby disconnecting the power supply to the load. When the load returns to normal, the first field-effect transistor unit 100 and the second field-effect transistor unit 200 re-enter the stable operating state. In this way, short-circuit protection and self-recovery can be achieved through a simple circuit structure, which is beneficial to improving the reliability of electronic equipment.
[0030] The first field-effect transistor (FET) unit 100 uses a P-type FET, which can also be connected to external components such as resistors and capacitors. The second FET unit 200 uses an N-type FET, which can also be connected to external components such as resistors and capacitors. The control terminal of the second FET unit 200 is connected to a first current-limiting resistor, which is also connected to the output terminal of the first FET unit 100. The unidirectional conduction unit 300 uses a diode. The input terminal of the unidirectional conduction unit 300 is connected to a first current-limiting resistor, which is also connected to the input power supply. The first current-limiting resistor limits the current of the first FET unit 100, the second FET unit 200, and the unidirectional conduction unit 300 to prevent overload and provide protection. The output terminal of the unidirectional conduction unit 300 is connected to a second current-limiting resistor, which is also connected to the input power supply. The capacitive unit 400 uses a single capacitor or a capacitor bank. The capacitor bank can include multiple capacitors connected in series, parallel, or series-parallel to realize the charging and discharging function of the capacitor. The output of the first field-effect transistor unit 100 is connected to a capacitor filter unit.
[0031] The following reference Figure 2 The working principle of the power supply short-circuit protection circuit in this embodiment will be explained.
[0032] To simplify the circuit structure, the circuit uses PMOS transistor Q1 as an example of the first field-effect transistor unit 100, NMOS transistor Q2 as an example of the second field-effect transistor unit 200, diode D1 as an example of the unidirectional conduction unit 300, capacitor C1 as an example of the capacitive unit 400, resistors R1 and R2 as examples of the first and second current-limiting resistors respectively, and capacitor C2 as an example of the capacitor filtering unit. The control terminal of the second field-effect transistor unit 200 is also connected to a third current-limiting resistor, such as resistor R3.
[0033] Assuming power is applied at time t0, at the instant of power-on, based on capacitor characteristics, capacitor C1 can be considered short-circuited at time t0. Therefore, the voltage drop across PMOS transistor Q1 is Vgs = Vd - Vbat ≈ -Vbat, where Vd is the forward voltage drop across diode D1 and Vbat is the voltage across VCC_IN. At this moment, according to PMOS transistor characteristics, PMOS transistor Q1 is in the on-state, opening the power supply path. Since the gate input of NMOS transistor Q2 is in a high-impedance state, its voltage drop is Vgs = Vbat. According to NMOS transistor characteristics, the on-state of NMOS transistor Q2 causes the voltage drop across PMOS transistor Q1 to be -Vbat. At this point, PMOS transistors Q1 and NMOS transistor Q2 interlock, ensuring the power supply path is effectively open.
[0034] Assuming that PMOS transistor Q1 and NMOS transistor Q2 are fully turned on at time t1, the protection circuit is in normal working condition. Simultaneously, resistor R2 completes the charging of capacitor C1, and the voltage across capacitor C1 equals Vbat. Due to the presence of diode D1, the voltage across capacitor C1 will remain constant.
[0035] Assuming a short circuit occurs in the subsequent circuit at time t2, at the instant of the short circuit, the VGs of NMOS transistor Q2 is 0, and at this moment, NMOS transistor Q2 is turned off. Since the voltage of capacitor C1 is equal to Vbat and the gate of PMOS transistor Q1 has a high input impedance, the gate voltage of PMOS transistor Q1 will be quickly pulled up to Vbat, so Vgs of PMOS transistor Q1 is 0, causing PMOS transistor Q1 to turn off, thus cutting off the power supply path and completing the short circuit protection for the power supply and the subsequent circuit. This protection circuit will continue to operate normally until the short circuit fault in the subsequent circuit is repaired and power is restored.
[0036] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.
Claims
1. A power supply short-circuit protection circuit, characterized in that, include: The first field-effect transistor unit (100) has an input terminal and an output terminal. The input terminal of the first field-effect transistor unit (100) is used to connect to an input power supply, and the output terminal of the first field-effect transistor unit (100) is used to connect to a load. The second field-effect transistor unit (200) has a polarity opposite to that of the first field-effect transistor unit (100). The input terminal of the second field-effect transistor unit (200) is connected to the control terminal of the first field-effect transistor unit (100), and the output terminal of the second field-effect transistor unit (200) is connected to the reference voltage terminal. The control terminal of the second field-effect transistor unit (200) is connected to the output terminal of the first field-effect transistor unit (100). The unidirectional conduction unit (300) has its input terminal connected to the control terminal of the first field-effect transistor unit (100). The output terminal of the unidirectional conduction unit (300) is connected to a capacitive unit (400) and is connected to the reference voltage terminal through the capacitive unit (400). Both the input terminal and the output terminal of the unidirectional conduction unit (300) are also connected to the input power supply.
2. The power supply short-circuit protection circuit according to claim 1, characterized in that, The first field-effect transistor unit (100) adopts a P-type field-effect transistor.
3. The power supply short-circuit protection circuit according to claim 1 or 2, characterized in that, The second field-effect transistor unit (200) adopts an N-type field-effect transistor.
4. The power supply short-circuit protection circuit according to claim 3, characterized in that, The control terminal of the second field-effect transistor unit (200) is connected to a first current-limiting resistor, and is connected to the output terminal of the first field-effect transistor unit (100) through the first current-limiting resistor.
5. The power supply short-circuit protection circuit according to claim 1, characterized in that, The unidirectional conduction unit (300) uses a diode.
6. The power supply short-circuit protection circuit according to claim 5, characterized in that, The input terminal of the unidirectional conduction unit (300) is connected to a first current-limiting resistor and is connected to the input power supply through the first current-limiting resistor.
7. The power supply short-circuit protection circuit according to claim 1, 5, or 6, characterized in that, The output terminal of the unidirectional conduction unit (300) is connected to a second current-limiting resistor, and is connected to the input power supply through the second current-limiting resistor.
8. The power supply short-circuit protection circuit according to claim 1, characterized in that, The capacitive unit (400) is a single capacitor or a group of capacitors.
9. The power supply short-circuit protection circuit according to claim 1, characterized in that, The output terminal of the first field-effect transistor unit (100) is connected to a capacitor filter unit.
10. An electronic device, characterized in that, Includes the power supply short-circuit protection circuit as described in any one of claims 1 to 9.