Multi-bit SDM with successive approximation core ADC, e.g. for mobile communications, uses reference DAC in core-ADC and as feedback-DAC of modulator

摘要

A multi-bit sigma-delta modulator (SDM) has a successive approximation (SA) ADC as a core ADC and a reference DAC. The multi-bit delta modulator is designed so that the reference DAC is used in common in both the core-ADC as well as feedback-DAC of the complete multi-bit SDM. Preferably the modulator works in a spatial multiplexing manner so that for every transfer between the reference DAC and the successive approximation circuit, the DAC also it also connects with the feedback loop circuit.