Jitter Challenges and Reduction Techniques at 10 Gb/s and Beyond

Abstract

The bandwidths of high-speed input/output (I/O) links keep increasing to meet the ever-growing demands for high-speed communications. The data rates for the leading edge high-speed I/O standards have already increased to around 10 Gb/s, including 10 GB Ethernet (GBE, 10 Gb/s, or 4 times 10.3125 Gb/s, and 10 times10.3125 Gb/s for Ethernet 40 G/100 G), 8 times fibre channel (8.5 Gb/s), and PCI Express Gen 3 (at 8 Gb/s). At those data rates, the total available timing budget become less, data-dependent jitter gets severe, and jitter amplification becomes significant. This paper focuses on these jitter challenges and associated mitigation/reduction technologies, including jitter tracking via clock recovery, eye-opening via equalizations, and DCD cancellation via delay elements to avoid jitter amplification.