Test equipment for DAC’s performance assessment: design and characterization

In this paper, the authors present a new practicable method and the related measurement station for digital-toanalog converters (DAC) characterization. The method relies on the accurate reconstruction of a sine-wave test signal generated by the DAC under test based on the simultaneous acquisitions of the signal attained by filtering the DAC output and the difference between the DAC output and the filter output. Thus, due to straightforward data processing, the signal generated by the DAC is gained with a resolution much better than the resolution (usually poor) of the analog-to-digital converter (ADC) exploited for the acquisition. The main feature of the method is the ease of implementation that requires only traditional electronics and actual measurement instrumentation. In this paper, the authors also suggest simple rules aimed at evaluating the resolution achievable by each guessed measurement station. To confirm the expected encouraging outcomes, experimental results obtained through a measurement station implemented by using a two-channel 8-bit digital scope and based on the presented method are discussed. In particular, signals generated by 12- and 14-bit DACs have been acquired and processed with the measurement station and reconstructed, with a resolution greater than 17 equivalent bits, due to the proposed method.