A 1-GHz Analog Multiphase PWM Using a Single Synchronization Source

A high frequency multiphase PWM with highly linear duty cycle and high synchronization between phases is presented. A single synchronization source to induce a triangular-like signal, based on an RC circuit, is used. Theoretical derivations show that this signal assists in the generation of a duty cycle with high linearity. Also, from the same source and due to the symmetry of the signal, 4 resulting phases with high synchronization between them are generated. A 5-stage fully differential ring oscillator is used to generate the clock signal. The circuit was simulated in a 65 nm technology, showing an operational frequency of 1 GHz with a relative error of less than 8%, which decreases at lower frequencies, and a consumption of 1.15 mW.