This application bulletin will provide the reader with an understanding of test methods for audio digital-to-analog converters (DACs). In particular, delta-sigma (∆Σ) DACs require a special understanding due to the nature of their architecture. The dynamic specifications of interest for an audio DAC are THD+N (total harmonic distortion + noise), dynamic range, channel separation, and idle channel noise (often referred to as SNR, signal-to-noise ratio). There are many possible digital audio applications, but only CD-DA (reproduction of digital audio from a compact disc) has a standard specification defined by EIAJ (Electronic Industry Association of Japan).
