PURPOSE: To integrate the switched capacitor filter without being affected of increase in a chip area and a stray capacitance or the like.

CONSTITUTION: Capacitors Cs forming the switched capacitor are connected in series. In the case of connecting two Cs in series, the combined capacitance Cs' is expressed as Cs'=1/{(1/Cs)+(1/Cs)}=Cs/2. When the Cs' is regarded as a capacitance of one capacitor, the capacitance (area) of the Cs' is halved in comparison with one Cs. When N sets of capacitors C are connected in series, the area of the combined capacitor is 1/N.