Patent ID: 7285924

Claim:
An LCD (Liquid Crystal Display) backlight driving circuit comprising: a PWM (Pulse Width Modulation) controller sending controlling signals; two transistors receiving the controlling signals and sending two low-voltage pulse signals respectively; an inverter converting the two low-voltage pulse signals to a high-voltage AC (Alternating Current) power; two lamps, wherein each of the lamps receives the high-voltage AC power and then is grounded; two overvoltage protection circuits, wherein the two voltage protection circuits are connected to the two lamps respectively; a voltage feedback module connected to the two lamps, and controlling the PWM controller to be turned on or turned off; a current feedback module connected to one of the two lamps, and controlling the PWM controller to be turned on or turned off; and a double-bridge circuit connected between the two lamps, and connected to the current feedback module for controlling the PWM controller to be turned on or turned off, wherein the inverter comprises a center-tapped transformer, the center-tapped transformer converts the two low-voltage pulse signals to the high-voltage AC power.