CN202651774U - Under-voltage protection circuit in LED drive chip - Google Patents
Under-voltage protection circuit in LED drive chip Download PDFInfo
- Publication number
- CN202651774U CN202651774U CN 201220343542 CN201220343542U CN202651774U CN 202651774 U CN202651774 U CN 202651774U CN 201220343542 CN201220343542 CN 201220343542 CN 201220343542 U CN201220343542 U CN 201220343542U CN 202651774 U CN202651774 U CN 202651774U
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- comparator
- load resistance
- protection circuit
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Abstract
The utility model mainly discloses an under-voltage protection circuit in an LED drive chip. The under-voltage protection circuit comprises a comparator, a crystal triode, a load resistor 1, a load resistor 2, and two not gates; wherein the crystal triode, the load resistor 1 and the load resistor 2 are connected in series and ground, the connection point of the load resistor 1 and the load resistor 2 is connected with an input end of the comparator, the other input end of the comparator is connected with a VDD comparison voltage, and the output end of the comparator is sequentially connected with the two not gates in series, and finally an output voltage is formed. The VCC voltage is sampled by voltage division and compared with the VDD comparison voltage, so as to realize the under-voltage protection function. The structure of the under-voltage protection circuit is simple, and the under-voltage protection circuit is applied to the LED drive chip circuit, so as to ensure the stability of the working voltage in the drive chip.
Description
Technical field
The utility model relates to led chip art field, and is relevant with the under-voltage protecting circuit in a kind of LED driving chip especially.
Background technology
The LED illuminating lamp self has very strong advantage as the illuminating product of a new generation: energy-conservation, brightness is high, high efficiency, life-span length, environmental protection etc., because the LED illumination waits these advantages has been arranged, and has determined the wide of market prospects, the enormous amount of demand.Each LED lamp must be equipped with a LED driving power.Wherein, the LED driving power cost for the LED street lamp accounts for 8%-10% of whole light fixture cost; The LED driving power cost of LED domestic lighting lamp accounts for 1/3rd of whole light fixture cost.
Some does not have the under-voltage protection measure in the LED driving chip, thereby can cause the unsettled phenomenon of supply voltage.The inventor drives for LED and has done research, designs the under-voltage protecting circuit in a kind of LED driving chip, and this case produces thus.
The utility model content
The purpose of this utility model provides the under-voltage protecting circuit in a kind of LED driving chip, and is simple in structure, effectively protects the chip working stability.
In order to achieve the above object, the utility model is achieved through the following technical solutions:
A kind of LED drives the under-voltage protecting circuit in the chip, comprises comparator, transistor, load resistance one, load resistance two, two not gates; Transistor, load resistance one, load resistance two threes form series connection ground connection, be connected to an input of comparator at the tie point of load resistance one, load resistance two, another input of comparator connects the VDD comparative voltage, the output of comparator two not gates of connecting successively finally form output voltage.
After described two not gates series connection, by a grounding through resistance.
After adopting technique scheme, the utlity model has many beneficial effects:
The input of the comparator in the utility model is sampled by two load resistance dividing potential drops, and sampling is rear by dividing potential drop sampling VCC voltage, and compares with the VDD comparative voltage, realizes under-voltage protection function.The utility model is simple in structure, is applied to LED and drives in the chip circuit, can guarantee to drive the stability of operating voltage in the chip.
Description of drawings
Fig. 1 is the circuit diagram of the utility model preferred embodiment.
Embodiment
By reference to the accompanying drawings, preferred embodiment is described in further details to the utility model.
A kind of LED drives the under-voltage protecting circuit in the chip, comprises comparator 1, transistor Q, load resistance one R1, load resistance two R2, two not gate A1, A2.
Input voltage VCC is from the emitter input of transistor Q, and the collector electrode of transistor Q is series load resistance one R1, load resistance two R2 successively, last ground connection.Wherein the series connection point of load resistance one R1, load resistance two R2 forms dividing point, access to one of them input of comparator 1, another input of comparator 1 connects the VDD comparative voltage, and the output of comparator 1 once connect two not gate A1, A2 finally form output voltage.
In order to ensure stable, after not gate A2, by a resistance R 3 ground connection of connecting.
The input sampling of the comparator 1 in the utility model is rear by dividing potential drop sampling VCC voltage, and compares with the VDD comparative voltage, realizes under-voltage protection function.The utility model is simple in structure, is applied to LED and drives in the chip circuit, can guarantee to drive the stability of operating voltage in the chip.
Above-described embodiment only is used for explaining inventive concept of the present utility model, but not to the restriction of the utility model rights protection, allly utilizes this design that the utility model is carried out the change of unsubstantiality, all should fall into protection range of the present utility model.
Claims (2)
1. a LED drives the under-voltage protecting circuit in the chip, it is characterized in that: comprise comparator, transistor, load resistance one, load resistance two, two not gates; Transistor, load resistance one, load resistance two threes form series connection ground connection, be connected to an input of comparator at the tie point of load resistance one, load resistance two, another input of comparator connects the VDD comparative voltage, the output of comparator two not gates of connecting successively finally form output voltage.
2. a kind of LED as claimed in claim 1 drives the under-voltage protecting circuit in the chip, it is characterized in that: after described two not gates series connection, by a grounding through resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220343542 CN202651774U (en) | 2012-07-16 | 2012-07-16 | Under-voltage protection circuit in LED drive chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220343542 CN202651774U (en) | 2012-07-16 | 2012-07-16 | Under-voltage protection circuit in LED drive chip |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202651774U true CN202651774U (en) | 2013-01-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220343542 Expired - Fee Related CN202651774U (en) | 2012-07-16 | 2012-07-16 | Under-voltage protection circuit in LED drive chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202651774U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102751706A (en) * | 2012-07-16 | 2012-10-24 | 绍兴文理学院 | Undervoltage protection circuit of LED (light-emitting diode)-driven chip |
-
2012
- 2012-07-16 CN CN 201220343542 patent/CN202651774U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102751706A (en) * | 2012-07-16 | 2012-10-24 | 绍兴文理学院 | Undervoltage protection circuit of LED (light-emitting diode)-driven chip |
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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: 20130102 Termination date: 20150716 |
|
| EXPY | Termination of patent right or utility model |