Linearity evaluation of high-speed sampling ADC board

There are growing demands on the evaluation of accuracy for high-speed analog-to-digital converters which are increasingly needed in electrical metrology these days. Here, we have developed a system to measure the linearity error of analog-to-digital converters by adopting a reference sampling voltmeter and a dummy waveform generator. With the measurement setup, we evaluated the linearities for three units of Δ-Σ analog-to-digital converter, NI-5922, combined with three different PXI chassis. We found that the maximum linearity error can change with the PXI chassis up to about 15 μV/V.