A 1.8-pJ/bit 16×16-Gb/s source synchronous parallel interface in 32nm SOI CMOS with receiver redundancy for link recalibration

Abstract

A 16×16-Gb/s source-synchronous I/O is reported in 32nm SOI CMOS. The bus-level receiver includes redundant RX lanes to enable lane recalibration with reduced power and area overhead. The I/O also includes an 8:1 TX serializer with 8-phase clocking, and an active-inductor-based RX CTLE whose outputs form current mirrors with the inputs of the RX samplers. A phase rotator based on current-integrating phase interpolator cores is described, with architecture and circuit improvements to performance as compared to prior art. 16-Gb/s link measurements over Megtron-6 traces demonstrate efficiencies of 1.8pJ/bit (0.75" traces) and 1.9pJ/bit (10" traces) with >30% timing margin, with the TX, RX, and PLL operating from 1V supplies.