Patent ID: 8106987

Claim:
An apparatus for processing an analog input signal, the apparatus comprising: a first reference sampling capacitor circuit that is arranged for sampling the analog input signal at a first time to provide a first sampled reference level; a second reference sampling capacitor circuit that is arranged for sampling the analog input signal at a third time to provide a second sampled reference level, wherein the third time is subsequent to the first time; an input sampling capacitor circuit that is arranged for sampling the analog input signal at a second time between the first time and the third time to provide a first sampled input signal level, wherein the input sampling capacitor circuit is also arranged for sampling the analog input signal at a fourth time subsequent to the third time to provide a second sampled input signal level; an amplifier circuit that is dynamically configured in one of a first hold configuration, a second hold configuration, and an initialization configuration, wherein a differential output of the amplifier circuit is substantially zero in the initialization configuration, and wherein the differential output of the amplifier circuit in the first hold configuration and in the second hold configuration is dependent upon the analog input signal as sampled; and first and second feedback capacitor circuits that are arranged in cooperation with the first and second reference sampling capacitor circuits, the input sampling capacitor circuit, and the amplifier circuit such that: the differential output corresponds to a difference between the first sampled input signal level and the first sampled reference level at the third time; and the differential output corresponds to a difference between the second sampled input signal level and the second sampled reference level at a fifth time subsequent to the fourth time.