Open-loop sample and hold topologies generally provide the fastest implementation of the sampling function. However, the precision obtained with such configurations is typically much lower than can be achieved with alternative closed-loop architecture. In design where an MOS transistor is used as sampling switch, input-dependent charge associated with the fast turn-off of the switch is often the principal source of sampling error. This charge injection introduces a pedestal error, in the hold mode that results in both nonlinearity and gain error. Since the resistance of switch is nonlinear as...