A 0.2–2 Gb/s 6x OSR Receiver Using a Digitally Self-Adaptive Equalizer

This paper presents a very robust 6x OSR receiver for 0.2-2 Gb/s binary NRZ signals, introducing an adaptive equalizer that is auto-calibrating on sample data statistics for reliable data recovery in presence of excessive intersymbol interference, noise and crosstalk. The proposed time domain analysis of the data eye obtained with the oversampling architecture is used to tune the equalizer transfer characteristic. The auto-calibration scheme is fully implemented in the digital domain, resulting in a hardware and power efficient architecture with low process-voltage-temperature (PVT) sensitivity. This robust and highly digitized receiver is demonstrated in 0.18 CMOS technology and is able to equalize variable cable losses up to 22 dB @ 1 GHz. The self-adaptive equalizer solution occupies only 0.05 and consumes 9 mW from a 1.8 V supply and can handle up to 20 m 100 Omega STP cable @ 2 Gb/s. The entire receiver consumes 110 mW operating at 2 Gb/s with bit error rates of better than < 10^-12.