Patent ID: 8344650

Claim:
A backlight driving system to drive a plurality of lamp groups, the backlight driving system comprising: a phase controller to generate a plurality of phase signals; a pulse width modulate (PWM) controller to generate PWM signals; a plurality of power stages to receive direct current (DC) signals from an external power source and convert the DC signals to alternative current (AC) signals according to the PWM signals; a plurality of transformers to receive and boost up the AC signals to drive the plurality of lamp groups; a plurality of switch circuits connected between the external power source and the plurality of power stages, to alternatively transmit the DC signals from the external power source and the PWM signals from the PWM controller to the plurality of power stages under the control of the plurality of phase signals, so as to control outputs of the plurality of power stages; and a feedback circuit connected between the PWM controller and the plurality of lamp groups to detect current flowing through the plurality of lamp groups to generate a feedback signal to the PWM controller; wherein the plurality of phase signals shift between positive and negative phases to correspondingly control the transmission of the plurality of switch circuits, and each of the plurality of switch circuits comprises a first end connected to the external power source to receive the DC signals, a second end connected to corresponding one of the plurality of power stages to output the DC signals, and a third end connected to the phase controller to receive a corresponding one of the plurality of phase signals.