Timing recovery methods for gigabit Ethernet

摘要

Gigabit Ethernet on category-5 cable is the high speed Ethernet LAN for twisted pair copper medium. Each gigabit Ethernet consists of multiple receive and transmit channels. The timing recovery system that controls the clock between receive and transmit channels requires a multi-phase high speed PLL. This paper reviews the different methods in generating high speed multi-phase PLLs, including the classical analog interpolating method, the "feedback phase selection" method, and the digital multiplexing and clock dividing method.