| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an output amplifier for a video signal, which not only includes muting and power saving functions but also prevents noise from occurring when current for the power saving is interrupted. Ž<P>SOLUTION: The output amplifier for the video signal includes an output portion (11) having a differential amplifier circuit which has a first current source (CC5) for supplying an operational current and input terminals to which the video signal and reference voltage are inputted, and a voltage buffer portion (12) which has an output transistor comprised of a bipolar transistor and second current source and which outputs a reference voltage by receiving constant voltage at the input terminal. In the output amplifier for the video signal so configured that the current of the first and second current sources is interrupted by a control signal from the outside, a third current source (CC2) provided on a route of which a base current of the output transistor in the voltage buffer portion flows is also interrupted when the current of the first current source (CC5) and second current source (CC4) is interrupted. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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