Patent ID: 8077139

Claim:
A driving circuit of a backlight module, wherein the backlight module includes a first light-emitting diode (LED) unit, the driving circuit comprising: a voltage conversion unit, coupled to a first end of the first LED unit for providing a driving voltage to the first LED unit; a current adjusting unit, coupled to a second end of the first LED unit for adjusting a conducted current of the first LED unit according to a first current adjusting signal; a current mapping unit, outputting a reference voltage; and a dimming unit, coupled between the current mapping unit and the current adjusting unit, and comprising a plurality of driving units, wherein a first driving unit outputs the first current adjusting signal according to a first pulse width modulation (PWM) signal, a first enable signal and the reference voltage, wherein the first driving unit comprises: an AND gate, having a first input terminal and a second input terminal respectively receiving the first PWM signal and the first enable signal; a N-type transistor, having a drain coupled to the reference voltage, a source coupled to the current adjusting unit and outputting the first current adjusting signal, and a gate coupled to an output terminal of the AND gate; and a P-type transistor, coupled between the reference voltage and ground, and a gate of the P-type transistor being coupled to the output terminal of the AND gate.