A 32 Gb/s Rx only equalization transceiver with 1-tap speculative FIR and 2-tap direct IIR DFE

Abstract

This paper presents an Rx only equalization (ROE) technique that eliminates all Tx equalizations to reduce power dissipation, circuit complexity, and cost. The proposed Rx consists of a CTLE, a 1-tap speculative FIR and 2-tap direct IIR DFE. A simpler Tx architecture owing to the ROE facilitates a wide bandwidth and energy efficient dual-mode (differential and single-ended) Tx operation. The proposed Tx consists of dual-mode 2:1 serializer/pre-drivers and main drivers. The transceiver was fabricated in a 65 nm CMOS technology. The Rx achieves BER <; 10<;sup>-12<;/sup> over a -22 dB loss PCB channel at 32 Gb/s with 0.62 pJ/b energy efficiency, and occupies 0.024 mm<;sup>2<;/sup>. The Tx has only 0.77 pJ/b and 0.40 pJ/b energy efficiency at 32 Gb/s in differential mode, and 32 Gb/s/pin in single-ended mode, respectively, and occupies only 0.002 mm<;sup>2<;/sup>.