Patent ID: 8067972

Claim:
A filter circuit, comprising: a voltage-current conversion portion that converts a voltage signal input to an input terminal to a current signal; a first capacitor unit comprising a group of first capacitors in electrical connection with the voltage-current conversion portion, wherein: the current signal is input to the first capacitors during a first charging period; and first outputs of the first capacitors are added to generate a first output current signal for the first capacitor group; a second capacitor unit comprising a group of second capacitors; and a connection node that electrically connects the first capacitor group to the second capacitor group, wherein: the first output current signal is input to the second capacitors during a second charging period; second outputs of the second capacitors are added to generate a second output current signal for the second capacitor group; the connection node comprises a reset switch electrically connected to ground and associated with a reset time period, activation of the reset switch during the reset time period causing a discharge to ground of the parasitic capacitance of at least one of the first capacitor group or the second capacitor group.