| 摘要 |
PURPOSE:To reduce remarkably the number of pins in case of integration by analog-multiplexing an analog video signal and a saw tooth wave signal and A/D-converting it. CONSTITUTION:An analog signal 1 is supplied to an analog multiplexer 4 and a control circuit 5, and the latter generates a control signal 13 to show flyback period of an analog video signal and supplies it to an saw tooth wave generator circuit 2 and a multiplexer 4. The circuit 2 generates a saw tooth wave during flyback period of the signal 13 and transmits it to the multiplexer 4, which switches the signal 1 to an output signal 14 of the circuit 2, and vice versa, and outputs it to an A/D convertor circuit 6. Thus a digitized signal is supplied to a digital signal processing circuit 12 enclosed with dash line and processed by a Y/C separator circuit 7, a Y signal processing circuit 8, a C signal processing circuit 9 and a color demodulation circuit 10, and signals R, G and B are supplied to a D/A convertor 11.
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