An improved analog-to-digital converter wherein a minimal amount of circuitry
is provided for conversion of an analog signal to a series of digital bits. A comparator
is provided for generating digital values to which the digital bits correspond.
A digital-to-analog converter is provided for generating, via successive approximation,
a feedback analog signal based on bits previously generated by the comparator.
The analog-to-digital converter compares the feedback analog signal to the input
analog signal, and based on the comparison generates a digital value that corresponds
to a digital bit. In the method of the invention, an analog signal is converted
to a digital value using the analog-to-digital converter, and a digital-to-analog
converter comprising two capacitors and a reference selector generates, via successive
approximation, a feedback analog signal that is applied to a comparator for comparison
to the input analog signal being digitized.