A mechanism for discharging parasitic capacitance at an input of an
operational amplifier, which is shared between two stages of a pipelined
analog-to-digital converter and/or two channels of signal processing
circuitry, before the amplifier configuration of the stages/channels is
switched. The discharging act occurs when a short reset pulse is
generated between two clock phases. The short reset pulse is applied to a
switch connected to the operational amplifier input. When the reset pulse
closes the switch, a discharge path is created and any parasitic
capacitance at the operational amplifier input is discharged through the
path. The discharging of the parasitic capacitance substantially
mitigates the memory effect and the problems associated with the memory
effect.