An adaptive current reversal comparator for synchronous switching
regulator comparison circuit for use in a switching regulator is
provided. The comparison circuit includes a voltage offset that is used
at least in part to compensate for a propagation delay of the comparison
circuit. The switching regulator includes an inductor and a synchronous
transistor. The comparison circuit also includes a timing circuit that
provides a threshold amount of time and an offset adjustment circuit. The
offset adjustment circuit preferably decreases the voltage offset of the
comparison circuit when a synchronous transistor control signal
transitions to an OFF state more than the threshold amount of time prior
to the discharge of an inductor. The comparison circuit also increases
the voltage offset of the comparison circuit when the synchronous control
signal transitions to an OFF state more than the threshold amount of time
following the discharge of the inductor.