A 56-Gb/s receiver front-end with a CTLE and 1-tap DFE in 20-nm CMOS

A 56-Gb/s receiver front-end suited for baud-rate clock recovery is demonstrated in 20-nm CMOS. Sharing the comparators for the data decision and phase detection minimizes the number of comparators in the front-end and reduces the power consumption. The front-end has a continuous-time linear equalizer followed by a 1-tap speculative decision-feedback equalizer. The front-end operates at 56Gb/s with a bit error rate of less than 10
⁻¹²
with a 0.4UI margin in the bathtub curve. It occupies 0.27mm
²
and consumes 177mW of power from a 0.9-V supply.