Patent ID: 9693418
Date: 2017-06-27
CPC Classifications: H05B,Y02B

Claim:
1. A light emitting diode (LED) driving chip having eight pins, the LED driving chip comprising: a current regulating circuit, arranged to selectively output a first current, a second current, a third current and a fourth current to a first pin, a second pin, a third pin and a fourth pin of the LED driving chip, respectively; a current control circuit, coupled to the current regulating circuit and a fifth pin, the current control circuit arranged to receive an adjusting signal from the fifth pin to control the first current, the second current, the third current and the fourth current; a feedback voltage control circuit, arranged to output a feedback voltage to a sixth pin according to a first specific voltage and a setting voltage, wherein the first specific voltage is selected from the first voltage, the second voltage, the third voltage and the fourth voltage corresponding to the first, the second, the third and the fourth pins, respectively; and a protection circuit, arranged to determine whether a voltage difference between a second specific voltage and the first specific voltage is larger than a threshold value, wherein the second specific voltage is selected from the first voltage, the second voltage, the third voltage and the fourth voltage; and when the voltage difference is larger than the threshold value, the protection circuit controls the current regulating circuit to stop conducting current to a specific pin corresponding to the first specific voltage to make a voltage of the specific pin no longer the first specific voltage, and the feedback voltage control circuit stops utilizing the voltage of the specific pin to output the feedback voltage.