CN204464965U - Under voltage protection circuit - Google Patents
Under voltage protection circuit Download PDFInfo
- Publication number
- CN204464965U CN204464965U CN201520156737.2U CN201520156737U CN204464965U CN 204464965 U CN204464965 U CN 204464965U CN 201520156737 U CN201520156737 U CN 201520156737U CN 204464965 U CN204464965 U CN 204464965U
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- China
- Prior art keywords
- branch road
- resistance
- earth point
- pnp triode
- connects
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- Expired - Fee Related
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Abstract
The utility model discloses the technical solution of the utility model is a kind of under voltage protection circuit of design, comprises DC supply input, earth point, PNP triode, NPN triode and under-voltage holding wire.The utility model under voltage protection circuit, whether it can detect input voltage lower than rated range.
Description
Technical field
The utility model relates under voltage protection circuit.
Background technology
The under voltage protection of existing DC power supply has much room for improvement.
Utility model content
The purpose of this utility model is to provide a kind of under voltage protection circuit, and whether it can detect input voltage lower than rated range.
For achieving the above object, the technical solution of the utility model is a kind of under voltage protection circuit of design, comprises DC supply input, earth point, PNP triode, NPN triode and under-voltage holding wire;
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 the collector electrode of PNP triode by the second branch road; Described second branch road is in series with the 3rd resistance and the 4th resistance successively by DC supply input to PNP triode collector electrode;
The base stage of described PNP triode connects the first branch road by the 3rd branch road; The tie point of described 3rd branch road and the first branch road is between the first resistance and the second resistance; Described 3rd 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 4th branch road; Described 4th branch road is provided with the 5th resistance;
The described base stage of NPN triode is connected with the collector electrode of PNP triode;
The emitter of described NPN triode connects earth point;
The collector electrode of described NPN triode connects earth point by the 5th branch road; Described 5th branch road is provided with the second electric capacity;
Described under-voltage holding wire connects the collector electrode of NPN triode.
Advantage of the present utility model and beneficial effect are: provide a kind of under voltage protection circuit, and whether it can detect input voltage lower than rated range.
Adopt the first resistance and the second resistance composition voltage detecting 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; under-voltage holding wire connects power management IC; power management IC can carry out powered-down according to the conducting of under-voltage holding wire, reaches the object of under voltage protection.
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 under voltage protection circuit, comprises DC supply input INPUT+, earth point AGND, PNP triode Q1, NPN triode Q2 and under-voltage holding wire VL;
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 the collector electrode C of PNP triode Q1 by the second branch road; Described second branch road is in series with the 3rd resistance R3 and the 4th resistance R4 successively by DC supply input INPUT+ to PNP triode Q1 collector electrode C;
The base stage B of described PNP triode Q1 connects the first branch road by the 3rd branch road; The tie point of described 3rd branch road and the first branch road is between the first resistance R1 and the second resistance R2; Described 3rd branch road is provided with diode, and the positive pole of described diode 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 4th branch road; Described 4th branch road is provided with the 5th resistance R5;
The described base stage B of NPN triode Q2 is connected with the collector electrode C of PNP triode Q1;
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 5th branch road; Described 5th branch road is provided with the second electric capacity C2;
Described under-voltage holding wire VL 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. under voltage protection circuit, is characterized in that, comprises DC supply input, earth point, PNP triode, NPN triode and under-voltage holding wire;
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 the collector electrode of PNP triode by the second branch road; Described second branch road is in series with the 3rd resistance and the 4th resistance successively by DC supply input to PNP triode collector electrode;
The base stage of described PNP triode connects the first branch road by the 3rd branch road; The tie point of described 3rd branch road and the first branch road is between the first resistance and the second resistance; Described 3rd 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 4th branch road; Described 4th branch road is provided with the 5th resistance;
The described base stage of NPN triode is connected with the collector electrode of PNP triode;
The emitter of described NPN triode connects earth point;
The collector electrode of described NPN triode connects earth point by the 5th branch road; Described 5th branch road is provided with the second electric capacity;
Described under-voltage holding wire connects the collector electrode of NPN triode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520156737.2U CN204464965U (en) | 2015-03-19 | 2015-03-19 | Under voltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520156737.2U CN204464965U (en) | 2015-03-19 | 2015-03-19 | Under voltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204464965U true CN204464965U (en) | 2015-07-08 |
Family
ID=53671792
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520156737.2U Expired - Fee Related CN204464965U (en) | 2015-03-19 | 2015-03-19 | Under voltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204464965U (en) |
-
2015
- 2015-03-19 CN CN201520156737.2U patent/CN204464965U/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 |
Granted publication date: 20150708 Termination date: 20190319 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |