A type of filter in integrated-circuit form that relies on a device consisting of a capacitor and a switch (see diagram). The switching between v_in and v_o results in the charging and discharging of the capacitor, which creates an average current flow between v_in and v_o dependent on the value of the capacitance and thus resembles the action of a resistor. In MOS technology it is difficult to fabricate the large values of resistance required by some filter networks. The switched capacitor filter enables the replacement of the resistive element of RC active filter designs, allowing them to be fabricated as an integrated circuit.

Switched capacitor filter