A low noise programmable clock multiplier based on a pulse injection-locked oscillator with a highly-digital tuning loop

This paper introduces a pulse injection-locked oscillator (PILO) that provides low jitter clock multiplication of a clean input reference clock. A mostly-digital feedback circuit provides continuous tuning of the oscillator such that its natural frequency is locked to the injected frequency. The prototype uses a 50 MHz reference input to generate a 3.2 GHz output with integrated phase noise, reference spur, and estimated deterministic jitter of 134 fs (rms), - 63.4 dBc, and 211 fs (peak-to-peak), respectively.