Patent ID: 7514882

Claim:
A lamp driving device, comprising: a pulse width modulation circuit arranged to generate a pulse width modulation signal; a phase splitter coupled to the pulse width modulation circuit and arranged to split the pulse width modulation signal into a plurality of phased signals having different phases, wherein pulses of each phased signal are non-overlapping with those of another phased signal, wherein the phase splitter comprises: a plurality of flip-flops coupled to the pulse width modulation circuit, and arranged to receive the pulse width modulation signal and a reset signal to generate flip-flop signals; and a plurality of logic gates coupled to the pulse width modulation circuit and the flip-flops, and arranged to receive the pulse width modulation signal and the flip-flop signals to generate the phased signals; a plurality of transformers each having a secondary winding respectively coupled to a lamp; and a plurality of bridge circuits each having a plurality of switches and being controlled by corresponding one of the phased signals to conduct a current alternately flowing to and from a primary winding of corresponding one of the transformers.