Patent ID: 7486217
Filing Date: 2009-02-03
Classification: H03M

Abstract:
1. An A/D converter, comprising: an A/D converter for pipeline use, that converts an analogue input signal into a digital signal; a D/A converter that switches between pipeline use and delta-sigma modulation use according to a mode in use; an analogue adder that subtracts an output of the D/A converter from the analogue input signal; and a hybrid stage comprising an analogue operation circuit that receives as input an output of the analogue adder and functions as an amplifier in a pipeline mode and as an integrator in a delta-sigma mode, wherein the hybrid stage comprises: an A/D converter for pipeline use, that converts an analogue input signal into a digital signal; a first D/A converter for pipeline use; a second D/A converter for delta-sigma modulation use; an analogue adder that subtracts an output of the first and second D/A converters from the analogue input signal; and an analogue operation circuit that receives as input an output of the analogue adder and functions as an amplifier in the pipeline mode and as an integrator in the delta-sigma mode.