IC for automatic detection of a positive or negative vision modulation, picture carrier detection and video signal identification

The design and construction of an integrated circuit that automatically detects the modulation sense (positive or negative) of received TV signals is described. The integrated circuit works with a multistandard intermediate frequency (IF) video demodulator and offers other functions such as an analog AFC (automotive frequency control) output; blocks tuning pulses delivered during up- or down-frequency searches when a picture carrier is detected in a range of +or-500 KHz to the (IF) picture carrier; and provides a video identification circuit for sound muting facilities. This circuit is intended to operate as part of multistandard TV IF equipment.