PURPOSE: To set the optional characteristics for a switched capacitor filter (SCF), by transferring selectively the electric charge of plural capacitors to an integrating capacitor based on a binary weight coefficient.

CONSTITUTION: Sampling capacitors C1∼C5 are set at 1, 1, 2, 4 and 8PF respectively with C6 set at 16PF, and -5, -6, -7 and -8 square of 2 are realized for the low-order 4 bits of an 8-bit binary weight coefficient. In this case, switches S20 and S21 are switched toward an arrow mark by the clock pulse in the state under which both the ends are earthed for the capacitors C1∼C5. Then the C1 is connected in series to the C2∼C5 which are connected in parallel, and the bit of the weight coefficient is swiched to the operator side or the earth side according to the timing pulse and to 1 or 0 for a switch circuit SW2. When only the C2 is switched, the potential V4 is set at 1/16.V1 with the switch S21 turned off. Thus the output voltage V2 is set at 1/256.V1 to obtain the minimum capacity.