A 1.68–23.2-Gb/s Reference-Less Half-Rate Receiver With an ISI-Tolerant Unlimited Range Frequency Detector

Abstract

This paper presents a reference-less half-rate receiver with an unlimited range frequency detector (URFD) for 13.8X continuous rate operation. To tolerate channel loss induced inter-symbol interference (ISI), the receiver is integrated with a continuous time linear equalizer (CTLE) and a 2-Tap decision feedback equalizer (DFE) on the same chip. Incorporating with the novel pulse width based URFD, the date rate of the receiver is limited by the frequency tuning range of the voltage-controlled oscillator (VCO). The energy efficiencies of the whole receiver and clock data recovery (CDR) are about 2.39 and 0.97 pJ/bit respectively. Implemented in a TSMC 28-nm CMOS process, the active area is 0.056 mm.