This paper reports advances made in the development of an all digital audio power amplifier or power digital-to-analogue converter. A previous paper (1) reported simulation and theoretical results and demonstrated that they were in agreement. A hardware test rig has been constructed for both one and two-sided digital (uniformly sampled) pulse width modulators and it is shown that the one sided modulator confirms the theory previously reported, but that the two sided modulator does not, though its performance in some cases exceeds that predicted. Since the original paper other work in the area has been reported (2) which claims that uniform and naturally sampled pulse width modulation are essentially the same and therefore that criteria developed for naturally sampled systems may be used to design uniformly sampled systems. To refute this assertion a two sided naturally sampled modulator has been constructed and the results so obtained are compared with those of the uniformly sampled system.
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.