PURPOSE: To obtain an excellent characteristic by using plural operational amplifiers in time division so as to simplify the constitution of a recursive filter.

CONSTITUTION: The recursive filters are connected by 2-stage in cascade and constituted with the 1st switch groups S11∼S14, the 2nd switch groups S21∼S24, the 1st and 2nd operational amplifiers OP1, OP2, delay circuits DY11, DY12 and DY21, DY22 constituting two sample-and-hold circuits. The switch groups S11∼ S14 are turned on at each T/2 with a drive signal 1 in synchronizing with a period T of an input frequency signal at an input terminal IN and the switch groups S21∼S24 are turned on at each period T/2 with drive signals of different phases and driven alternately in time division. The sample pulse 1 of the period T and a sample pulse 2 having the period T and different phase are held respectively to the delay circuits DY11, DY12 and DY21, DY22. Then the constitution of the filter is simplified so as to improve the characteristic.