MEASUREMENT OF ADC INTEGRAL NONLINEARITY VIA DFT

摘要

the paper presents a new methodology, based on the Discrete Fourier Transform of the output, for measuring the integral nonlinearity of an ADC. The new method, unlike the usual histogram test, gives the best polynomial approximation (the "smooth part") of the integral nonlinearity, which is responsible for the spurious harmonics above the ADC noise floor, and can be performed with great accuracy and repeatability with as few as 8,000 samples, irrespective the ADC resolution. This makes this test by far faster than the histogram test for high-resolution devices.