| 摘要 |
PROBLEM TO BE SOLVED: To provide a video amplifier capable of driving a load by DC coupling without a capacitor for DC cutting, and preventing a noise generated due to operation of a charge pump circuit from being mixed with an image signal. SOLUTION: The video amplifier which inputs a video signal including a synchronizing component and outputs an output signal for cable driving comprises a clock signal generating circuit 12 which separates the synchronizing component from the video signal and generates a clock signal having rise variation and fall variation in a blanking period of the video signal from the separated synchronizing component, a charge pump circuit which is supplied with a positive voltage from a positive power supply provided for the video amplifier and driven with the clock signal from the clock generator to generate a negative voltage at an output, and a video signal output circuit 14 which is supplied with a positive voltage from the positive power supply and a negative voltage from the charge pump circuit and at least amplifies the current of the input video signal to output the video signal for cable driving. COPYRIGHT: (C)2008,JPO&INPIT
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