Analog-to-digital converter with reduced average input current and reduced average reference current

Abstract

Novel system and methodology for sampling analog input signals to reduce an average common-mode input current caused by unbalanced nodes of an input signal source. An analog-to-digital (A/D) conversion system for converting an analog input signal supplied by a signal source having first and second nodes may have a first sampling circuit coupled to the first node for sampling the input signal with respect to a reference signal and configured so as to provide a substantially zero total charge taken from the first node during a first sampling process, and a second sampling circuit coupled to the second node for sampling the input signal with respect to the reference signal and configured so as to provide a substantially zero total charge taken from the second node during a second sampling process. In response to first and second output signals respectively produced by the first and second sampling circuits, an output circuit may provide common-mode rejection.