Design Methodologies for Low-Jitter CMOS Clock Distribution

Clock jitter negatively affects the performance of sampling circuits such as high-speed wireline transceivers and data converters. With CMOS buffers being increasingly used for the distribution of precise clocks in advanced technologies, it is important to understand their limitations and explore design tradeoffs. This tutorial provides quantitative analyses of the main sources of jitter in CMOS clock distribution: power supply induced jitter, jitter generation, and jitter amplification. Minimizing the number of buffers along the clock distribution network while still maintaining fast rise-fall times and ensuring proper settling of all clock waveforms will minimize the impact of all jitter sources. Following these guidelines can simultaneously reduce power supply noise sensitivity and power consumption of the clock distribution circuits. These conclusions are backed up by simulation and measurement results of two 16-nm FinFET clock distribution networks.