Provided herein are self-calibrating timing circuits and methods for use
in a sync separator. A comparator compares a video signal to a video
reference voltage to produce a sliced sync signal that has a frequency
that is equal to a scan frequency of a horizontal sync embedded in the
video signal. A first converter converts the sliced sync signal to a
control signal having an amplitude or magnitude that is inversely
proportional to the scan period of the horizontal sync embedded the video
signal. A second converter converts the voltage control signal to a timer
signal that has timed intervals that are that are inversely proportional
to the amplitude or magnitude of the control signal, and thus
proportional to the scan period of the horizontal sync embedded in the
video signal. These timed intervals produced in accordance with
embodiments of the present invention are easily and precisely scalable,
allowing them to be used to discriminate various timing features embedded
in video signals. This abstract is not intended to be a complete
description of, or limit the scope of, the invention.