Abstract: An analog-to-digital converter circuit includes a series of substantially identical stages, each receiving an incoming analog voltage. Reference terminals of the initial stage are biased to an initial reference voltage and ground, with subsequent first and second reference voltages determined in each preceding stage. A voltage divider consisting of a pair of matched resistors provides an output of one-half the reference voltage to a comparator. The comparator, having as its other input the incoming analog signal, generates a binary "one" or "zero" depending on whether the incoming signal is greater or less than the voltage divider output. The binary signal also controls switching circuitry which provides first and second reference signals to the next stage of the A/D converter. Responsive to a binary one from the converter, these reference signals are the reference voltage and one-half the reference voltage, respectively.