A novel approach to high speed digital pulse-formers based on ring oscillators for pwm and class-D applications

摘要

In this paper, a new concept for a high speed, high resolution digital pulse-former is presented. A digital pulseformerbasically maps each input data word (sample) into a binary pulse of corresponding width. Such binarypulse-length modulated signals are incorporated in digital class-D amplifiers and pwm applications. In our approacha synchronous digital counter converting the "rough" part of the input sample is combined with a ringoscillator serving as "fine" counter. This hybrid configuration yields a drastically increased resolution whilemaintaining moderate clock rates. Results of a first discrete implementation of this concept are discussed.