Sigma-delta pulse-width-modulated signal generator circuit

摘要

A circuit for generating a pulse-width-modulated signal comprises a phase-locked loop (PLL) having a duty-cycle-insensitive phase comparator and a Sigma-Delta pulse width modulation circuit suitable for providing the voltage-controlled oscillator function of the PLL. Thereby, frequency of the signal generated is synchronized by the PLL to the specified frequency of a synchronization signal, and is thus independent of the duty cycle.