A novel on-chip mismatch measurement technique for Nyquist rate ADCs

This paper proposes a novel on-chip mismatch measurement technique for built In Self-Test (UIST) of Nyquist rate ADCs. The proposed solution consists mostly of a digital module, using a ternary stream as test stimulus and a sine wave fitting algorithm to estimate the Signal-to-Noise and Distortion Ratio (SNDR). The reference signal for the system is a periodical ternary stream generated internally on-chip in order to stimulate the converter. On chip stimulus generation eliminates the need of external analog input. In the proposed UIST scheme for the Nyquist ADC, a MASH2-0 architecture integrates the ADC under test and it is shown that the measured output SNDR of ΣΔ ADC with sine wave curve fitting closely relates to the ENOB of the ADC under test. Experimental results show that the correlation between the embedded self-test and a sinusoidal standard test are excellent, with a SNDR error smaller than 1 dB.