DIGITAL SIGMA MODULATOR AND ANALOG-TO-DIGITAL CONVERTER

摘要

PROBLEM TO BE SOLVED: To overcome such a problem as an increase in a circuit scale when a conventional ΣΔ modulator is constituted to obtain a reducing effect of a quantization error equivalent to that of the case of bit multiplexing a 1-bit quantizer 29 while using the 1-bit quantizer 29 in a feedback loop. SOLUTION: In a feedforward loop, a second subtracter 10 for calculating the quantization error is used together with a multi-bit quantizer 11.