An analog-to-digital converter converts a frequency-modulated signal into
a digital signal. The frequency-modulated signal is supplied to multiple
comparators, such as low-pass filters, which determine whether the signal
falls within their frequency ranges. The outputs of the comparators are
converted into a digital output signal, e.g., by fat-tree encoding. Each
comparator has a differently tuned capacitive load to cause a phase delay
in the input signal. When the phase-delayed and non-phase-delayed signals
are supplied to a D-Flop, the phase delay is determined by whether the
latch conditions are met.