PRECISION SAMPLING CIRCUIT

摘要

A sampling circuit includes an input voltage source; a first switch having an input operatively connected to the input voltage source; a sampling capacitor operatively connected to an output of the first switch; an operational amplifier having an inverting input operatively connected to the sampling capacitor; a second switch operatively connected across the inverting input of the operational amplifier and an output of the operational amplifier; and a second capacitor operatively connected to the output of the first switch. The first switch has a variable parasitic capacitance, and the second capacitor has a substantially more linear capacitance than the variable parasitic capacitance and is in parallel with the variable parasitic capacitance. A combined variable parasitic capacitance and capacitance of said switch capacitor is more linear than the variable parasitic capacitance of the first switch.