Patent ID: 8558821

Claim:
A power device capable of improving flicker of a liquid crystal display, the power device comprising: a direct current voltage/direct current voltage converter for generating a direct current low gate voltage; a common voltage circuit for receiving a polarity reversion signal generated by a timing control circuit, and generating an alternating current common voltage according to the polarity reversion signal; and a clamper coupled to the direct current voltage/direct current voltage converter and the common voltage circuit for receiving the direct current low gate voltage and the alternating current common voltage, outputting the alternating current common voltage, and outputting an alternating current low gate voltage according to the direct current low gate voltage and the alternating current common voltage, the clamper comprising: a capacitor having a first terminal coupled to the common voltage circuit for receiving the alternating current common voltage, and outputting the alternating current common voltage, and a second terminal for outputting the alternating current low gate voltage; a resistor having a first terminal coupled to the second terminal of the capacitor, and a second terminal coupled to ground; and a diode having an anode coupled to the second terminal of the capacitor, and a cathode coupled to the direct current voltage/direct current voltage converter for receiving the direct current low gate voltage, wherein the diode is conductive during a first low gate voltage period of the alternating current low gate voltage and is not conductive during a second low gate voltage period of the alternating current low gate voltage; wherein the alternating current low gate voltage is synchronized with the alternating current common voltage.