Minimal pre-charge technique implemented for switched-capacitor pipeline ADC

Slew rate limitation is a major cause of nonlinear settling error in switched capacitor circuits. In this paper we present a simple charge-sharing solution, by pre-charging the load capacitors properly, the initial input voltage step is minimized. The technique is simulated in a SC pipeline residue amplifier, and it provides 5.4 dB (nearly 1 bit) improvement in the settling accuracy with no additional active components. Alternatively, the same performance can be achieved by 20-30% bias current reduction in the op-amps.