Patent ID: 8077070

Claim:
An analog-to-digital converter apparatus comprising: a first stage comprising: a first charge storage device, for storing an input charge that corresponds to an analog input signal; a first comparator, for comparing a reference voltage against a voltage corresponding to the input charge as stored at the first charge storage device, and in response thereto, providing a first comparison signal; a first comparison result storage device, for storing the first comparison signal and to provide a first digital output signal; and a first charge transfer device, for transferring the stored input charge out of the first stage; a second stage comprising: a second charge storage device for storing the stored input charge as received from the first charge transfer device of the first stage, a charge redistribution device, the charge redistribution device providing a redistribution charge that depends on the first comparison signal; a second comparator, for comparing a reference voltage with the stored input charge and the redistribution charge, to provide a second comparison signal; and a second comparison result storage device, for storing the second comparison signal and to provide a second digital output signal.