An input capacitor and a plurality of reference capacitors sample an input voltage and reference voltages in a first period. A switch circuit connects the input capacitor and one of the reference capacitors between an output and an input of an amplifier in a second period. This mechanism causes a feedback gain to be "1" in the second period. Therefore, it is possible to reduce power consumption and noise.
Provided is a multi-bit pipeline analog-to-digital converter (ADC) having a merged capacitor switching structure. In a multiplying digital-to-analog converter (MDAC) used in the multi-bit pipeline ADC, switches are connected between the bottom plates of respective differential capacitors, thereby constantly maintaining a uniform input common mode voltage regardless of an input digital code. Thus, it is possible to improve the operating speed and performance of the MDAC.
A pipelined analog to digital converter comprises N stages, wherein N is an integer greater than one. A sample and integrate circuit communicates with at least two stages of the N stages. The sample and integrate circuit selectively samples a first voltage input to one of the at least two stages while integrating a difference between a sampled second voltage input of another one of the at least two stages and a second reference voltage to generate a second residue. The sample and integrate circuit selectively integrates a difference between the sampled first voltage and a first reference voltage to generate a first residue while sampling a second voltage input.
