A segmented thermometer coded DAC with deterministic dynamic element matching for high resolution ADC test

Dynamic element matching (DEM) is an effective way to achieve good average performance in the presence of device mismatch, yet it has not been widely adopted because of the time-local stationarity of the signal path. This paper presents a DEM approach to ADC testing in which low precision DEM DACs are used to generate stimulus signals for the ADCs under test. A deterministic DEM (DDEM) switching scheme is applied to a segmented thermometer coded DAC architecture. Detailed simulation results are presented to verify the expected performance of the proposed testing approach. The new approach is able to accurately test ADCs with linearity that exceeds that of the original DAC used as the signal generator. The new architecture is suitable for production test and built-in-self-test (BIST) environments where high linearity ADCs are difficult to test and characterize.