DIGITAL FILTER

摘要

There is provided a digital filter of simple configuration. A signal transmission unit TRT switches between an input signal Din and an addition output signal Qe in a predetermined order in synchronization with a predetermined frequency fa of higher frequency than a sampling frequency fs and outputs it as a switched supply signal Sin. An addition unit AX adds the switched supply signal Sin and a multiplication signal Qal from a calculation unit CAL2 and the like in synchronization with the predetermined frequency fa and outputs the added input signal S0. A calculation unit CAL1 multiplies the filter coefficient by a predetermined number of multiplier in synchronization with the predetermined frequency fa so as to generate a multiplied signal Qb0. An addition unit AY adds the multiplied signal Qb0 and the multiplied signal Qb1 from the calculation unit CAL3 and the like in synchronization with the predetermined frequency fa and outputs an addition output signal Qe indicating the addition result. The multiplication units CAL2 and CAL3 respectively input the added input signal S0 via a delay unit DLY and multiply the filter coefficient by a predetermined number of multipliers in synchronization with the predetermined frequency fa so as to generate multiplied signals Qa1 and Qb1, which are supplied to addition units A1 and B1 so as to be subjected to an addition processing. An output unit PUT outputs an addition output signal Qe as an output signal Dout synchronized with the sampling frequency fs.