Search

This article describes a 4 $\times $ 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.

This article presents a multiprotocol DSP-DAC-based SerDes architecture. The lookup table (LUT)-based DSP provides flexible number of taps for equalization, and soft switching driver allows 1.2-Vpp transmit swing to achieve higher SNR. The architecture employs cascaded phase-locked loop (PLL)-based flexible clocking to support a wide range of data rates from 10 to 112 Gb/s. The $LC$ PLL generates 10.25–14.5 GHz but distributes a divided version of the clock between 2.25 and 3.625 GHz with less than 140-fs integrated jitter. The local ring PLL multiplies the clock to 28 GHz but keeps the jitter less than 180 fs thanks to wide loop bandwidth. The transmitter is implemented in 7-nm FinFET consuming 175 mW with 1.56-pJ/bit efficiency.

This paper describes a 4 × 112 Gb/s digital receiver targeting Long Reach (LR) channels. The discrete time front-end overcomes gain-BW limitations to provide 10+dB gain at 28GHz. A 56GS/s ADC then converts the signal to 6-b digital consuming only 195mW. The following DFE-FFE based digital equalizer is capable of compensating 36 dB loss achieving BER of 2e-5. Furthermore, TDC and ISI filter based low latency timing recovery meets jitter tolerance specs over a wide range of data rates (25Gb/s NRZ to 106.25Gb/s PAM-4). The overall receiver consumes 338mW with 3.18pJ/bit energy efficiency

The paper presents the design of a 2.488 – 11.2 Gbps SerDes transceiver in a 40nm low-leakage CMOS process. The paper explores the architectural and circuit techniques used to meet the stringent requirements of the high-speed SerDes and to mitigate the performance impact of the low-leakage process. The transceiver makes use of a low-jitter LC PLL to enable high-reliability system design. A system modeling approach is also described, which is used for optimizing the architectural trade-offs. The design has 520fs RJ rms and consumes 30.1 mW/Gbps at 11.2 Gbps.

A 2.3 to 5GHz LC PLL is implemented in 65nm standard CMOS for 0.6 to 10Gb/s SerDes applications. The LC VCO is measured to have 67% coarse tuning range and worst-case hold range of 9.6%. The rms random jitter (RJ rms ) on the TX output with a clock pattern is measured to be 460fs at 5GHz and 548fs at 3.125GHz. The total power dissipated from the 1.8V, 1.0V supplies is 29mW at 5GHz.