PURPOSE: To reduce beats and error noises generated in sampling by cascading an LPF to a switched capacitor filter.

CONSTITUTION: The LPF2 is provided on the input side of a switched capacitor filter 4 in order to reduce beads between the clock of the filter and an input signal. The output signal of the LPF2 is applied to the filter 4 and capacitors in the filter are switched by the clock from a clock input terminal 5 to perform sampling and filtering. A sampling error noise generated in the filter 4 is superposed on the output signal of the filter 4. An LPE7 is provided on the output side of the filter 4 to remove the sampling error noise, outputting an analog signal containing neither beats nor error noises to an output terminal 8.