ADC-DSP-Based 10-to-112-Gb/s Multi-Standard Receiver in 7-nm FinFET

This article describes a 4 × 112 Gb/s digital receiver targeting long-reach (LR) channels. An SNR optimized approach is presented, which relaxes the ADC resolution requirement and the number of FFE taps without sacrificing BER. The discrete-time front end overcomes gain-BW limitations to provide 10+ dB gain at 28 GHz. A 56-GS/s ADC then converts the signal to 6-b digital consuming only 195 mW. The following DFE-FFE-based digital equalizer is capable of compensating 36-dB loss achieving a BER of 2e-5. Furthermore, TDC and ISI filter-based low-latency timing recovery meet jitter tolerance specs over a wide range of data rates from 10 to 112 Gb/s, including 28-Gb/s NRZ. The overall receiver consumes 338 mW with 3.18-pJ/bit energy efficiency.