DELTA SIGMA MODULATOR FOR REDUCING QUANTIZATION NOISE

摘要

PURPOSE: A delta sigma modulator for reducing quantization noise is provided to reduce quantization noise by correcting errors in a digital region. CONSTITUTION: A 1 bit quantizer(420) quantizes an applied analog signal and outputs the quantized digital signal. A 1 bit D/A converter(430) converts the quantized digital signal into a quantized analog signal. An input integration circuit series(410) subtracts a quantized analog output signal of the 1 bit D/A converter(430) from an analog input signal, integrates it and outputs the integrated output value to the first bit quantizer(420). A multi-bit quantizer(440) quantizes an output signal of the input integration circuit series(410) and outputs the quantized digital signal. An error correcting unit(450) receives the digital output signal of the multi-bit quantizer(440) and the digital output signal of the 1 bit quantizer(420) and corrects an error. A delay element(460) delays the quantized digital signal of the 1 bit quantizer(420). A subtracter(470) subtracts an output signal of the error correcting unit(450) from an output signal of the delay element(460) and outputs the subtraction result.