An 8-to-16GHz 28nm CMOS clock distribution circuit based on mutual-injection-locked ring oscillators

We propose and demonstrate an 8 to 16GHz clock distribution circuit using mutual-injection-locked ring oscillators. It distributes synchronous clock signals by mutually coupling the neighboring ring oscillators through the transconductors. It enables low swing clock distribution with minimal load capacitance, resulting in the fastest among the injection-locked ring-oscillator-based clock distribution circuits. A test chip was fabricated in a 28nm CMOS technology. It achieved a -102dBc/Hz of the phase noise at 1MHz offset and the rms jitter of 2.84ps, while consuming 22.9mW from a 0.85V power supply.