A New Sigma–Delta Modulator Architecture for Testing Using Digital Stimulus

Sigma-delta modulators are commonly used in high-resolution analog-to-digital converters (ADCs). Testing this type of modulator requires a high-resolution test stimulus, which is difficult to generate. A new architecture for the modulator is proposed so that its performance can be determined using only digital test stimulus. This architecture does not need analog test stimuli, which is prone to distortion/noise while setting up the high-resolution modulator for testing. Simulation results show that this technique is capable of accurately determining the performance of a second-order sigma-delta modulator ADC.