CN204464966U - Voltage protection circuit - Google Patents
Voltage protection circuit Download PDFInfo
- Publication number
- CN204464966U CN204464966U CN201520157071.2U CN201520157071U CN204464966U CN 204464966 U CN204464966 U CN 204464966U CN 201520157071 U CN201520157071 U CN 201520157071U CN 204464966 U CN204464966 U CN 204464966U
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- China
- Prior art keywords
- branch road
- resistance
- earth point
- supply input
- voltage
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- Expired - Fee Related
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- Emergency Protection Circuit Devices (AREA)
Abstract
The utility model discloses a kind of voltage protection circuit, comprise DC supply input, earth point, PNP triode, NPN triode and voltage signal line.The voltage protection circuit that the utility model provides, whether it can detect input voltage below or above rated range, and power management IC can carry out powered-down according to the conducting of voltage signal line, reaches the object of overvoltage protection, prevents late-class circuit from damaging.
Description
Technical field
The utility model relates to voltage protection circuit.
Background technology
Under voltage, the overvoltage protection of existing DC power supply have much room for improvement.
Utility model content
The purpose of this utility model is to provide a kind of voltage protection circuit, and whether it can detect input voltage below or above rated range.
For achieving the above object, the technical solution of the utility model is a kind of voltage protection circuit of design, comprises DC supply input, earth point, PNP triode, NPN triode and voltage signal line;
Described DC supply input connects earth point by the first branch road; Described first branch road is in series with the first resistance and the second resistance successively by DC supply input to earth point; Described second resistance two ends are also parallel with the first electric capacity;
Described DC supply input also connects earth point by the second branch road; Described second branch road is provided with the second electric capacity;
Described DC supply input also connects earth point by the 3rd branch road; Described 3rd branch road is in series with the first voltage stabilizing didoe, the second voltage stabilizing didoe, the 3rd resistance and the 4th resistance successively by DC supply input to earth point; Described 4th resistance two ends are also parallel with the 3rd electric capacity;
The base stage of described PNP triode connects the first branch road by the 4th branch road; The tie point of described 4th branch road and the first branch road is between the first resistance and the second resistance; Described 4th branch road is provided with diode, and the positive pole of described diode is connected with the base stage of PNP triode;
The emitter of described PNP triode connects earth point by the 5th branch road; Described 5th branch road is provided with the 5th resistance;
The collector electrode of described PNP triode is connected with the 3rd branch road, and the tie point of described PNP triode collector electrode and the 3rd branch road is between the 3rd resistance and the 4th resistance;
The base stage of described NPN triode is connected with the 3rd branch road, and the tie point of described NPN transistor base and the 3rd branch road is between the 3rd resistance and the 4th resistance;
The emitter of described NPN triode connects earth point;
The collector electrode of described NPN triode connects earth point by the 6th branch road; Described 6th branch road is provided with the 4th electric capacity;
Described voltage signal line connects the collector electrode of NPN triode.
Advantage of the present utility model and beneficial effect are: provide a kind of voltage protection circuit, and whether it can detect input voltage below or above rated range.
Adopt the first resistance and the second resistance composition Undervoltage detection circuit; when the voltage of DC supply input is lower than certain value; PNP triode conducting is driven by diode; and then NPN triode ON; voltage signal line connects power management IC; power management IC can carry out powered-down according to the conducting of voltage signal line, reaches the object of under voltage protection.
Adopt the first voltage stabilizing didoe, the second voltage stabilizing didoe, the 3rd resistance and the 4th resistance composition overvoltage detection circuit; when DC supply input voltage is higher than certain value; NPN triode ON; voltage signal line connects power management IC; power management IC can carry out powered-down according to the conducting of voltage signal line; reach the object of overvoltage protection, prevent late-class circuit from damaging.
Accompanying drawing explanation
Fig. 1 is schematic diagram of the present utility model.
Embodiment
Below in conjunction with drawings and Examples, embodiment of the present utility model is further described.Following examples only for clearly the technical solution of the utility model being described, and can not limit protection range of the present utility model with this.
The technical scheme that the utility model is specifically implemented is:
As shown in Figure 1, a kind of voltage protection circuit, comprises DC supply input INPUT+, earth point AGND, PNP triode Q1, NPN triode Q2 and voltage signal line VT;
Described DC supply input INPUT+ connects earth point AGND by the first branch road; Described first branch road is in series with the first resistance R1 and the second resistance R2 successively by DC supply input INPUT+ to earth point AGND; Described second resistance R2 two ends are also parallel with the first electric capacity C1;
Described DC supply input INPUT+ also connects earth point AGND by the second branch road; Described second branch road is provided with the second electric capacity C2;
Described DC supply input INPUT+ also connects earth point AGND by the 3rd branch road; Described 3rd branch road is in series with the first voltage stabilizing didoe ZD1, the second voltage stabilizing didoe ZD2, the 3rd resistance R3 and the 4th resistance R4 successively by DC supply input INPUT+ to earth point AGND; Described 4th resistance R4 two ends are also parallel with the 3rd electric capacity C3;
The base stage B of described PNP triode Q1 connects the first branch road by the 4th branch road; The tie point of described 4th branch road and the first branch road is between the first resistance R1 and the second resistance R2; Described 4th branch road is provided with diode D3, and the described positive pole of diode D3 is connected with the base stage B of PNP triode Q1;
The emitter E of described PNP triode Q1 connects earth point AGND by the 5th branch road; Described 5th branch road is provided with the 5th resistance R5;
The collector electrode C of described PNP triode Q1 is connected with the 3rd branch road, and the tie point of described PNP triode Q1 collector electrode C and the 3rd branch road is between the 3rd resistance R3 and the 4th resistance R4;
The base stage B of described NPN triode Q2 is connected with the 3rd branch road, and the tie point of described NPN triode Q2 base stage B and the 3rd branch road is between the 3rd resistance R3 and the 4th resistance R4;
The emitter E of described NPN triode Q2 connects earth point AGND;
The collector electrode C of described NPN triode Q2 connects earth point AGND by the 6th branch road; Described 6th branch road is provided with the 4th electric capacity C4;
Described voltage signal line VT connects the collector electrode C of NPN triode Q2.
The above is only preferred implementation of the present utility model; should be understood that; for those skilled in the art; under the prerequisite not departing from the utility model know-why; can also make some improvements and modifications, these improvements and modifications also should be considered as protection range of the present utility model.
Claims (1)
1. voltage protection circuit, is characterized in that, comprises DC supply input, earth point, PNP triode, NPN triode and voltage signal line;
Described DC supply input connects earth point by the first branch road; Described first branch road is in series with the first resistance and the second resistance successively by DC supply input to earth point; Described second resistance two ends are also parallel with the first electric capacity;
Described DC supply input also connects earth point by the second branch road; Described second branch road is provided with the second electric capacity;
Described DC supply input also connects earth point by the 3rd branch road; Described 3rd branch road is in series with the first voltage stabilizing didoe, the second voltage stabilizing didoe, the 3rd resistance and the 4th resistance successively by DC supply input to earth point; Described 4th resistance two ends are also parallel with the 3rd electric capacity;
The base stage of described PNP triode connects the first branch road by the 4th branch road; The tie point of described 4th branch road and the first branch road is between the first resistance and the second resistance; Described 4th branch road is provided with diode, and the positive pole of described diode is connected with the base stage of PNP triode;
The emitter of described PNP triode connects earth point by the 5th branch road; Described 5th branch road is provided with the 5th resistance;
The collector electrode of described PNP triode is connected with the 3rd branch road, and the tie point of described PNP triode collector electrode and the 3rd branch road is between the 3rd resistance and the 4th resistance;
The base stage of described NPN triode is connected with the 3rd branch road, and the tie point of described NPN transistor base and the 3rd branch road is between the 3rd resistance and the 4th resistance;
The emitter of described NPN triode connects earth point;
The collector electrode of described NPN triode connects earth point by the 6th branch road; Described 6th branch road is provided with the 4th electric capacity;
Described voltage signal line connects the collector electrode of NPN triode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520157071.2U CN204464966U (en) | 2015-03-19 | 2015-03-19 | Voltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520157071.2U CN204464966U (en) | 2015-03-19 | 2015-03-19 | Voltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204464966U true CN204464966U (en) | 2015-07-08 |
Family
ID=53671793
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520157071.2U Expired - Fee Related CN204464966U (en) | 2015-03-19 | 2015-03-19 | Voltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204464966U (en) |
-
2015
- 2015-03-19 CN CN201520157071.2U patent/CN204464966U/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150708 Termination date: 20190319 |