Audio testers needs to generate high-fidelity tones covering audio ranges (20 Hz to 20 kHz) and extend to hundreds of kilohertz. Typically, test stimuli are sine tones, and their purity is defined by total harmonic distortion (THD) and signal to noise ratio (SNR).

Audio testing systems are built with a high-performance audio DAC or precision DAC to generate a high-fidelity pure sine tones for testing. The resolution of these DACs ranges from 16 - 20 bits, with low noise and very low glitch energy.

Currently, designers use delta-sigma DAC topologies to generate audio signals, which produce out-of-band noise requiring additional digital signal processing logic and noise shaping filter. The additional digital signal processing adds extra information for correctness that is not present in the original signal. Also, it increases the overall system solution size and cost.