Two phase sampling for a delta sigma modulator

摘要

A delta sigma modulator provides dual phase sampling of analog input and/or a reference voltage. This dual phase sampling may be realized using a switched capacitor circuit having dual legs with a capacitor on each such leg. The dual phase sampling of the reference voltage poses a complication that mandates the necessity of providing a compensation signal. The delta sigma modulator is provided with appropriate circuitry to provide a compensation signal that compensates for the reduced signal level due to the dual sampling. In particular, the delta sigma modulator compensates for the reduced level of the output from an integrating amplifier circuit due to the timing necessary to implement the dual sampling approach.