ADC Spectral Testing with Signal Amplitude Drift and Simultaneous Non-coherent Sampling

Spectral testing is a vital category in modern measurement industry. The challenge is to cost-effectively test the ADCs accurately. Among many test requirements, maintaining input test signal stability and achieving coherent sampling are one of the bottlenecks for accurate testing of the ADC. If these stringent test requirements are not met, accurate spectral test results of the ADC cannot be obtained. This paper presents a method that simultaneously relaxes the requirements of precise control over source amplitude, and of the need for coherent sampling. By dividing the output data into segments, accurate estimation of the drift fundamental in each segment can be obtained, by removing the estimated drift fundamental and replacing with a coherent, non-drift fundamental in time domain, accurate spectral results can be achieved. Extensive simulation results have validated the accuracy and robustness of the proposed method. Furthermore, measurement results have verified the proposed method by accurately obtain spectral results of the ADC under test.