| 摘要 |
PURPOSE:To simplify the constitution of a PLL circuit by using a multiplier used to the PLL circuit also to a contrast circuit. CONSTITUTION:A multiplier 226 which is used to a contrast circuit 400 is used also to a PLL circuit 401 for a digital TV device which uses a PLL circuit for control of the sample phase. That is, two multiplexers 411 and 412 are provided at the input side of the multiplier 226, and a luminance signal 224 and a contrast control signal 225 are selected in a picture period. Then a new luminance signal 227 is delivered from the multiplier 226. While a hue signal 215 and an error signal 405 of the circuit 401 are selected within a horizontal flyback time, and the multiplier 226 is used also to the circuit 401. The circuit 401 controls the sample phase of an A/D converter 207 by the output 210 of a phase wave detection circuit 209 containing the multiplier 226. |
