Frequency and Amplitude Domain DAC-ADC Co-Testing Using Ternary Signals

The parametric estimation of devices in a signal chain, including the cascade of a digital-to-analog converter (DAC), a low-pass filter, and an analog-to-digital converter (ADC), is considered in this article. Frequency- and amplitude-domain procedures are presented for the estimation of the DAC output levels and ADC transition levels connected in a loopback configuration, including a low-pass filter in-between. A special class of source signals is used to perform estimation of the DAC and filter parameters. Estimation is based on a selection of excited frequencies to avoid uncertainties caused by DAC nonlinearities. An amplitude-domain estimator is used to measure the ADC integral nonlinearities by using the empirical distribution function of the ADC input signal. It is shown that high estimation accuracy can be achieved for all identifiable parameters in the signal chain. Theoretical, simulation, and experimental results are presented to validate the proposed procedure.