Patent ID: 8203525

Claim:
A dual-lamp driving circuit for driving a first discharge lamp and a second discharge lamp, the dual-lamp driving circuit comprising: a first frequency switch control circuit configured to receive a first enable signal, and output a first frequency switch signal based on the first enable signal; a second frequency switch control circuit configured to receive a second enable signal, and output a second frequency switch signal based on the second enable signal; a pulse-width modulation control circuit connected to the first frequency switch control circuit and the second frequency switch control circuit, and configured to output various pulse-width modulation control signals based on alternative one of the first frequency switch signal and the second frequency switch signal; a first power stage circuit configured to receive and convert an external electrical signal into a first square-wave signal based on the pulse-width modulation control signal from the pulse-width modulation control circuit; a second power stage circuit configured to receive the pulse-width modulation control signal under the direction of the second enable signal, and to receive and convert the external electrical signal into a second square-wave signal based on the received pulse-width modulation control signal; a first conversion circuit connected between the first power stage circuit and the first discharge lamp, and configured to convert the first square-wave signal into a first sine wave signal able to drive the first discharge lamp; a second conversion circuit connected between the second power stage circuit and the second discharge lamp, and configured to convert the second square-wave signal into a second sine wave signal able to drive the second discharge lamp; and a feedback circuit configured to feed back a first current signal through the first discharge lamp and a second current signal through the second discharge lamp to the first frequency switch control circuit and the second frequency switch control circuit respectively, so as to control the outputs of the first frequency switch control circuit and the second frequency switch control circuit.