A new ADC fast testing method based on the unified error model

Some of analogue to digital converter (ADC) errors such as missing code and errors with multiperiodical characters are nowadays markedly suppressed by technology advance. The residual errors expressed by the differential non-linearity and impact of analogue signal conditional circuits can be modelled by the unified behavioural error model which is one-dimensional image in the code domain. The model can be divided into a high and a low code frequency component. The paper presents two new test methods for low code frequency component determination. The first one is based on synchronous detection of the higher harmonics in ADC output record spectrum. The second one uses the repeating sinewave best fitting method to estimate the harmonics in ADC output record spectrum. The known harmonics enable the identification of low code frequency model parameters.