The new design of sigma-delta modulator with lower bits and its application

This paper is devoted to the discussion of a new kind of sigma-delta modulator as signal expression, by which the higher-bit input signal can be represented as a lower-bit digital signal. The quantized noise shaping and noise frequency spectrum are discussed and compared with the conventional sigma-delta modulator. The theoretic analysis shows that the new modulator is stable. A kind of DDC based on this modulator is designed and simulated.