A high-precision .DELTA..SIGMA. modulator reduces nonlinear noise due to
the use of a multibit DAC and has little hardware and power consumption.
A digital signal is DA converted and fed back to a subtraction circuit
supplied with an analog signal. The DAC used in this feedback circuit
uses a DAC (DWADAC) that includes a weighted pointer so that input
digital signals are supplied in order to a plurality of segment elements
that construct the DAC. In this DWADAC, the construction and number of
the pointer is set based on the type and order of the filter disposed
before the ADC.