The operating characteristics of a dynamic comparator is used to
automatically change the resolution of a sloped or ramped
analog-to-digital converter (ADC) by switching the comparator on and off
between first (slow) and second (fast) clock frequencies and comparing
the amplitude of a sampled input signal against a ramp input signal. The
slow clock frequency is first used to determine the area of interest,
while the fast clock frequency is then used to zoom into a high
resolution area of interest.