18.4 A 200GS/s 8b 20fJ/c-s Receiver with >60GHz AFE Bandwidth for 800Gb/s Optical Coherent Communications in 5nm FinFET

The post-COVID era has seen an unprecedented rise in activities requiring high bandwidth consumption such as remote working, streaming, VR, and AR. With the recent breakthroughs in AI and the introduction of Chat GPT, data transport and interconnect fabrics of data centers are being stressed to the limits and forced to scale up even more rapidly than their traditional pace. This is leading to a throughput expansion rate that is faster than existing thermal handling capability while forcing the power form factors of present infrastructures to remain the same. Such constraints place circuit designers and architectures in the critical path of a data-driven technological scaling evolution, ultimately leading to a common quest for ever more efficient transceivers that can simultaneously address this rapid bandwidth growth while ensuring an ever lower power footprint. The envelope of what is possible in the transceiver design community is constantly being tested and redefined, where traditional analog-front-end (AFE) bandwidth and rates of data converters are relentlessly pushed to the edge of the technology limits. Motivated by the same spirit in this paper, we present an energy efficient 8b 200GS/s receiver fully integrated in an 800G coherent DSP with a 20fJ/c-s and 60GHz AFE bandwidth, fabricated in a 5nm FinFET process.