A system and method directed to using a dither signal during conversion of
an analog input signal to a digital output signal without summing the
dither signal to the analog input signal. Such conversion may include
generating a digital dither signal with a pseudo-random noise generator
and converting the digital dither signal to an analog dither signal. The
analog dither signal is provided to an impedance network that
responsively produces a set of reference dither signals proportional to
the analog dither signal. A plurality of comparators compares the
proportional dither signals to the analog input signal so as to generate
a first output code. A dither signal reference code that indicates the
effects of passing the dither signal through the analog-to-digital
converter is subtracted from the first output code so as to produce a
second output code that is a digital representation of the analog input
signal.