CN210724187U - Input over-voltage and under-voltage protection circuit - Google Patents
Input over-voltage and under-voltage protection circuit Download PDFInfo
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- CN210724187U CN210724187U CN201921833541.7U CN201921833541U CN210724187U CN 210724187 U CN210724187 U CN 210724187U CN 201921833541 U CN201921833541 U CN 201921833541U CN 210724187 U CN210724187 U CN 210724187U
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Abstract
The utility model discloses an input overvoltage and undervoltage protection circuit, which comprises a first triode switch circuit, a second triode switch circuit, an input bleeder circuit or an enabling circuit, a switch diode and a main control integrated chip IC, wherein the input end of the first triode switch circuit is respectively connected with the input bleeder circuit or the enabling circuit and the input end of the second triode switch circuit, the output end of the first triode switch circuit is respectively connected with the input other end of the second triode switch circuit and the cathode of the diode, the output end of the input bleeder circuit or the enabling circuit is connected with the anode of the diode and the enabling end of the main control integrated chip IC, the utility model can effectively carry out overvoltage protection on the power main control chip, broadens the input power supply voltage range, prevents the input voltage from being damaged due to overhigh voltage and has simple structure, is convenient for production and application.
Description
Technical Field
The utility model relates to a power electronic technology field especially relates to an input and cross undervoltage protection circuit.
Background
Along with the rapid development of electronic technology in China, more and more electronic products are provided, various intelligent devices, LED lighting, chargers and the like need power supply, electronic devices such as general low-voltage intelligent devices and the like need direct-current power supply, the power supply of the devices has a certain power supply range, if the input voltage of the devices exceeds the range, permanent damage can be caused to components inside the electrical devices, and the devices are completely damaged, while most of the existing overvoltage protection schemes adopt an operational amplifier comparison circuit as an input overvoltage protection circuit, the cost is higher, a power supply needs to be additionally connected, the circuit design is complicated, the devices are not suitable for being used in a medium-sized and small-sized power supply, or a special overvoltage protection IC for special operation and amplification is adopted, but the devices are not easy to purchase, the cost of the special overvoltage protection IC is high, and therefore, an input overvoltage and undervoltage protection circuit with higher cost is urgently needed, to meet the actual need.
SUMMERY OF THE UTILITY MODEL
In order to ensure circuit performance, improve product performance price ratio and production efficiency to simplify circuit design, the utility model provides an input overvoltage crowbar, it can be effectual carries out overvoltage protection to power main control chip, has widened its input supply voltage scope, prevents it because of the too high damage of input voltage to simple structure, the production of being convenient for is used.
The purpose of the utility model can be realized by the following technical scheme:
an input over-voltage and under-voltage protection circuit comprises a first triode switch circuit, a second triode switch circuit, an input voltage division circuit or an enabling circuit, a switch diode and a main control integrated chip IC;
the first triode switch circuit is composed of a resistor R3, a resistor R4, a capacitor C2 and a triode V1, one end of the resistor R3 is connected with one end of a resistor R4, one end of a capacitor C2 and one input end of the triode V1, and the other end of the resistor R4 is connected with the other end of a capacitor C2;
the second triode switch circuit is composed of a resistor R5, a triode V2 and a capacitor C3, one end of the resistor R5 is connected with one input end of the triode V2, one output end of the triode V2 is connected with one end of the capacitor C3, and the other output end of the triode V2 is connected with the other end of the resistor R5;
the input voltage division circuit or the enabling circuit consists of a resistor R1, a resistor R2 and a capacitor C1, one end of the resistor R1 is connected with one end of a capacitor C1 and one end of a resistor R2, and one end of the capacitor C1 is connected with the other end of the resistor R2;
the input end of the first triode switch circuit is connected with the input voltage division circuit or the enabling circuit and the input end of the second triode switch circuit respectively, the output end of the first triode switch circuit is connected with the input other end of the second triode switch circuit and the cathode of the diode respectively, the output end of the input voltage division circuit or the enabling circuit is connected with the anode of the diode and the enabling end of the main control integrated chip IC, and the output end of the second triode switch circuit is connected with the power supply input end of the main control integrated chip IC.
Further, the triode V1 is a common NPN type triode, and the triode V2 is a high-voltage NPN type triode.
Furthermore, the other ends of the resistor R1, the resistor R3 and the resistor R5 are connected to a power supply IN line.
The utility model has the advantages that:
(1) the utility model avoids the great increase of power supply cost and research and development production cost caused by the model selection of the main chip device of the power supply, thereby improving the research and development and production efficiency;
(2) the utility model can realize the power supply to the power main chip in a wider range of input voltage;
(3) the utility model can effectively carry out overvoltage protection on the power supply main control chip, and prevent the power supply main control chip from being damaged due to overhigh input voltage;
(4) the utility model discloses simple structure, it is with low costs, the device is easily purchased, and the range of application is wide.
Drawings
The present invention will be further described with reference to the accompanying drawings.
Fig. 1 is a schematic view of the present invention.
Fig. 2 is a schematic diagram of a first triode switch circuit according to the present invention.
Fig. 3 is a schematic diagram of a second triode switch circuit according to the present invention.
Fig. 4 is a schematic diagram of the input voltage divider circuit or the enable circuit of the present invention.
Fig. 5 is a schematic diagram of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
As shown in fig. 1 to 5, an input over-voltage and under-voltage protection circuit includes a first triode switch circuit, a second triode switch circuit, an input voltage divider circuit or an enable circuit, a switching diode, and a main control integrated chip IC;
the first triode switching circuit consists of a resistor R3 of 100k omega, a resistor R4 of 510 omega, a capacitor C2 of 25V0.1uF and a triode V1, when the input voltage exceeds 120V, the resistors R3 and R4 divide the voltage into more than 0.6V by utilizing the switching characteristic of the triode V1, at the moment, the triode V1 is conducted, the collector voltage of the triode V1 is pulled to a low potential, one end of the resistor R3 is connected with one end of the resistor R4, one end of the capacitor C2 and one input end of the triode V1, and the other end of the resistor R4 is connected with the other end of the capacitor C2;
the second triode switch circuit consists of a resistor R5 of 150k omega, a triode V2 and a capacitor C3 of 250V0.1uF, wherein the capacitor C3 carries out filtering processing on the output voltage of an emitter of the triode V2 to prevent voltage overshoot of instantaneous turn-on, one end of the resistor R5 is connected with one input end of the triode V2, one output end of the triode V2 is connected with one end of the capacitor C3, and the other output end of the triode V2 is connected with the other end of the resistor R5;
the input voltage division circuit or the enabling circuit consists of a resistor R1 of 100k, a resistor R2 of 8.2k and a capacitor C1 of 25V0.1Uf, the resistor R1, the resistor R2 and the capacitor C1 divide, sample and filter input voltage, when the voltage is lower than 33V, namely the output sampling voltage is lower than 2.5V, namely lower than the undervoltage locking voltage value of a main control integrated chip IC of LM5025, the main control integrated chip IC turns off driving output, one end of the resistor R1 is connected with one end of the capacitor C1 and one end of the resistor R2, and one end of the capacitor C1 is connected with the other end of the resistor R2;
the input end of the first triode switch circuit is respectively connected with the input voltage division circuit or the enabling circuit and the input end of the second triode switch circuit, the output end of the first triode switch circuit is respectively connected with the input other end of the second triode switch circuit and the cathode of the diode, the output end of the input voltage division circuit or the enabling circuit is connected with the anode of the diode and the enabling end of the main control integrated chip IC, and the output end of the second triode switch circuit is connected with the power supply input end of the main control integrated chip IC.
The transistor V1 is a common NPN transistor, and the transistor V2 is a high-voltage NPN transistor.
The other ends of the resistor R1, the resistor R3 and the resistor R5 are connected to the power IN line.
The utility model discloses a theory of operation and mode:
the input voltage division circuit or the enabling circuit is connected with the first triode switch circuit and the second triode switch circuit by using the reverse characteristic of the diode, so that an undervoltage locking pin of the main control integrated chip IC is protected from being broken down and damaged due to overhigh input voltage, and when the input voltage is lower than 33V, namely the output sampling voltage is lower than 2.5V, the main control integrated chip IC is switched off to drive output; when the input voltage is higher than 120V, the triode V1 is conducted to pull down the voltage of the base electrode of the triode V2, so that the output voltage of the emitter of the triode V2 is pulled down, namely the input power supply voltage of the main control integrated chip IC is pulled to a low potential, the main control chip is further protected from being damaged by high-voltage overshoot at high moment or by mistakenly direct-current high-voltage power supply, and a rear-stage power circuit is protected from being conducted mistakenly due to input overvoltage; when the voltage is in the range of 33V to 120V, the maximum output voltage of an emitter of the triode V2 is lower than 86V, and the input of the main control integrated chip IC supplies power in the range of 13V to 90V, so that the safety of the main control integrated chip IC is guaranteed, and the input voltage range of the main control integrated chip IC is widened.
The utility model avoids the great increase of power supply cost and research and development production cost caused by the model selection of the main chip device of the power supply, thereby improving the research and development and production efficiency;
the utility model can realize the power supply to the power main chip in a wider range of input voltage;
the utility model can effectively carry out overvoltage protection on the power supply main control chip, and prevent the power supply main control chip from being damaged due to overhigh input voltage;
the utility model discloses simple structure, it is with low costs, the device is easily purchased, and the range of application is wide.
The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above description in any form, and although the present invention has been disclosed with reference to the preferred embodiment, it is not limited to the present invention, and any skilled person in the art can make modifications or changes equivalent to the equivalent embodiment of the above embodiments without departing from the scope of the present invention.
Claims (3)
1. An input over-voltage and under-voltage protection circuit is characterized by comprising a first triode switch circuit, a second triode switch circuit, an input voltage division circuit or an enabling circuit, a switch diode and a main control integrated chip IC;
the first triode switch circuit is composed of a resistor R3, a resistor R4, a capacitor C2 and a triode V1, one end of the resistor R3 is connected with one end of a resistor R4, one end of a capacitor C2 and one input end of the triode V1, and the other end of the resistor R4 is connected with the other end of a capacitor C2;
the second triode switch circuit is composed of a resistor R5, a triode V2 and a capacitor C3, one end of the resistor R5 is connected with one input end of the triode V2, one output end of the triode V2 is connected with one end of the capacitor C3, and the other output end of the triode V2 is connected with the other end of the resistor R5;
the input voltage division circuit or the enabling circuit consists of a resistor R1, a resistor R2 and a capacitor C1, one end of the resistor R1 is connected with one end of a capacitor C1 and one end of a resistor R2, and one end of the capacitor C1 is connected with the other end of the resistor R2;
the input end of the first triode switch circuit is connected with the input voltage division circuit or the enabling circuit and the input end of the second triode switch circuit respectively, the output end of the first triode switch circuit is connected with the input other end of the second triode switch circuit and the cathode of the diode respectively, the output end of the input voltage division circuit or the enabling circuit is connected with the anode of the diode and the enabling end of the main control integrated chip IC, and the output end of the second triode switch circuit is connected with the power supply input end of the main control integrated chip IC.
2. The input under-voltage protection circuit according to claim 1, wherein the transistor V1 is a normal NPN transistor, and the transistor V2 is a high-voltage NPN transistor.
3. The input under-voltage protection circuit of claim 1, wherein the other end of the resistor R1, the resistor R3 and the resistor R5 are connected to a power IN line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921833541.7U CN210724187U (en) | 2019-10-29 | 2019-10-29 | Input over-voltage and under-voltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921833541.7U CN210724187U (en) | 2019-10-29 | 2019-10-29 | Input over-voltage and under-voltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210724187U true CN210724187U (en) | 2020-06-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921833541.7U Active CN210724187U (en) | 2019-10-29 | 2019-10-29 | Input over-voltage and under-voltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210724187U (en) |
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2019
- 2019-10-29 CN CN201921833541.7U patent/CN210724187U/en active Active
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