Horizontal sync pulse minimum width logic

摘要

A horizontal sync separator that is capable of operating with horizontal sync signals of differing durations. A monostable is operated by the leading inverted negative edge of the horizontal sync pulse and generates a minimum duration horizontal pulse. The minimum duration horizontal pulse is applied along with the inverted negative horizontal pulse to an OR gate which outputs the longer of the two pulses. The arrangement assures proper video clamping during the horizontal back porch interval.