A 7-bit 7-GHz multiphase interpolator-based DPC for CDR applications

Abstract

This paper presents a 7-bit digital to phase converter (DPC) for high speed clock and data recovery (CDR) applications which is capable of generating multi-phase clocks at 7-GHz frequency. Fabricated in a standard 65-nm CMOS technology, the design introduces a modified phase interpolator (PI) and a quadrature phase corrector (QPC) to reduce the effect of the circuit imperfections on the DPC's resolution and linearity. Employing a 14-GHz quadrature reference clock, the DPC achieves DNL/INL of 0.7/6 LSB respectively while consuming 40.5 mW power from 1.05 V supply