| 摘要 |
<p>A method of recovering synchronization signals contained in a composite video signal. The synchronization signals are generally represented by voltage levels less than the blanking level of the video signal, and display data is represented by blanking level. A digital circuit (230) controls a biasing circuit (220) to generate a biasing voltage. A video signal is biased using the biasing voltage and the resulting biased video signal (225) is provided as an input to an operational amplifier (250). A second input of the operational amplifier is driven by a reference voltage (245). The digital circuit (230) monitors the output of the operational amplifier (250) and controls the biasing voltage (225) to cause the operational amplifier (250) to clip the display data from the biased video signal and generate a signal (123) representing synchronization signals.</p> |
