PURPOSE: To realize a PSRR (power supply fluctuation suppressing ratio) characteristic nearly equal to a positive and a negative power supply by using nearly the same number of operational amplifiers having different differential transistors (TRs) at the input stage and operational amplifiers having different polarity of differential TRs of the input stage.

CONSTITUTION: The primary section 51 is shown in a frame surrounded by broken lines and the secondary section 52∼the 6th order section 56 are shown in broken lines in the same may as in the case of the primary section. As operational amplifiers in use, an operational amplifier 57 having an NMOS input stage and an operational amplifier 58 having a PMOS input stage are used alternately. The difference in the PSRR characteristic at the positive power supply and the negative power supply is eliminated to realize a switched capacitor filter with excellent characteristics.