Patent ID: 7215262

Claim:
A digital signal processing apparatus for outputting a 1-bit digital signal by performing a delta sigma modulation process on a plurality of input signals, executing at least a filter function which causes the plurality of input signals to have different frequency characteristics, and a mixing function which mixes the plurality of signals each having a different frequency characteristic due to the at least one filter function, by a delta sigma modulator comprising: integrating means having a plurality of integrators; quantization means for subjecting an integrated output from the integrating means to quantization processing; a plurality of feedforward arithmetic means for performing arithmetic processing on the plurality of input signals by using feedforward coefficients of a plurality of systems corresponding to the plurality of signals and supplying an arithmetic result to the integrating means; and a plurality of feedback arithmetic means for performing arithmetic processing on the quantized output from the quantization means using feedback coefficients to feed back an arithmetic result to the integrating means, by using the approximately obtained feedforward coefficients of the plurality of systems and feedback coefficients, wherein the at least one filter function includes a first infinite impulse response filter having an order n 0 , a second infinite impulse response filter having an order n 1 , the mixing function includes a tertiary noise shaper having an order n 2 , and a number of the plurality of integrators is n 0 +n 1 +n 2 .