Patent ID: 7719202

Claim:
A light emitting diode (LED) driving circuit, mainly comprising: a commutation unit to transform an AC input cycle signal to a DC cycle signal; a switch unit which divides a driving power signal output to a LED and has a duty voltage value; a valley filled power factor correction circuit which receives the AC input cycle signal and stops conduction of the commutation unit when the voltage value of the AC input cycle signal is lower than a cutoff voltage value, the cutoff voltage value being higher than the duty voltage value; and a piezoelectric inverter which receives the driving power signal of the switch unit and regulates the signal to an AC modulated power signal within a duty range of the LED to drive the LED to emit light; wherein the commutation unit has a first output end and a second output end, the valley filled power factor correction circuit having a first circuit and a second circuit that consist respectively of a capacitor and a diode, and are located respectively at the first output end and the second output end, and another diode located between the first circuit and the second circuit.