摘要 |
<p>A single chip integrated circuit that performs the electronic functions of a monochrome television receiver with the exception of the RF tuner, sound channel, and power output stages. The circuit includes video IF/detector and video processing as well as a two loop horizontal phase locked loop for locking the horizontal flyback to the horizontal sync pulses. In addition, a vertical processing stage is related to the horizontal sync pulses, is included for producing vertical flyback. The circuit operates in a vertical narrow window mode when coincidence occurs between the vertical sync pulses and the output of a vertical countdown circuit to thereby reduce interference from noise and operates in a wide window mode when vertical sync pulses are lost or not yet acquired to allow fast acquisition of the vertical sync pulses.</p> |