| 摘要 |
PROBLEM TO BE SOLVED: To reduce unnecessary power consumption in a DAC and an amplifier circuit when an external device is not connected to a video signal output terminal in a device having the video signal output terminal to which the external device such as a television monitor is connected. SOLUTION: This video signal output control circuit is equipped with: a digital/analog conversion circuit; the amplifier circuit which amplifies an analog video signal; the video signal output terminal; an output resistor provided between the amplifier circuit and the video signal output terminal; an analog/digital conversion circuit which converts the analog video signal passing through the output resistor into a digital video signal and a control means for judging whether or not the external device is connected to the video signal output terminal on the basis of a level of the video signal output from the analog/digital conversion circuit and stopping operations of the digital/analog conversion circuit and the amplifier circuit when the external device is not connected. COPYRIGHT: (C)2008,JPO&INPIT
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