PURPOSE: To vary a cut-off frequency in a range wider than ever keeping constant the circuit constant of a non-sampling filter, by overlapping two switched capacitor filters(SCF).

CONSTITUTION: A clock on which n-number of frequency division is applied by a frequency divider 5, is inputted to a first SCF6, and an original clock is inputted to a second SCF7. And the cut-off frequencies of the first and the second SCFs 6 and 7 are decided corresponding to respective clock switched by a switch 9. The first SCF6 is the one for a signal processing, and the second SCF7 eliminates the clock leaking from the first SCF6, and the non-sampling filter 8 eliminates the clock leaking from the second SCF7. By setting relation between the cut-off frequency, and the clock frequency in each of the first SCF6, and the second SCF7 at a ratio of 1 to (m), the ratio between the cut-off frequency and the clock frequency for the signal processing of a system goes to 1 to(nm) by the n-number of frequency division, and the separation of noise by a signal and the clock can be easily performed.