PURPOSE: To obtain the output of plural different characteristic constants with one filter by changing the bracketing of an integrating capacitor and a clock frequency in accordance with the bracketing.

CONSTITUTION: At a time T2 (0) when a clock is an 'H' level, integrating capacitors C12 and C22 are connected between one side input terminal and the output terminal of arithmetic amplifiers 100 and 200 and integrating capacitors C11 and C21 are cut and separated. At such a time, integrating capacitors C11 and C21 hold the charge charged to a time T1 (0). Simultaneously, a clock CK3 where a period is T/2 is given to all switched capacitor equal resistances SC1∼SC4. To a time T2 (2), a clock S2 is made into the 'H' level, a switch 22 is turned on, an output VOBPF1 is sampled, charging is executed to a capacitor CS2, thereby, obtaining a sample/hold waveform VO2. By repeating a series of the action for a period 2T, the output of two different central frequencies fO1 and fO2 is obtained by VO1 and VO2 terminals.