A Low Jitter 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 proposed system is demonstrated with a prototype consisting of a custom 0.13 mu m integrated circuit with active area of 0.4 mm(2) and core power of 28.6 mW, along with an FPGA, a discrete DAC and a simple RC filter. Using a low jitter 50 MHz reference input, the PILO prototype generates a 3.2 GHz output with integrated phase noise, reference spur, and estimated deterministic jitter of 130 fs (rms), -63.9 dBc, and 200 fs (peak-to-peak), respectively.