US Patent 7683820 Charge-domain pipelined charge-redistribution analog-to-digital converter

A single-ended charge-domain pipeline of at least two stages is provided. Each stage comprises a charge-storage node, a charge-transfer circuit for conveying charge from said charge-storage node out of said stage, a charge-control capacitor connected to said charge-storage node and driven by a periodic clock voltage, a comparator which compares the voltage of said charge-storage node to a reference voltage, and a digital latch which latches the state of said comparator output under control of a second periodic clock voltage and provides a latched digital output from said stage. The second stage of the pipeline further includes a first charge-redistribution capacitor connected to the charge-storage node of the second stage and driven by a conditional voltage responsive to the latched digital output from the first stage. The charge output from each stage of said pipeline is substantially identical to the charge input to said stage.