A 28-Gb/s Receiver With Self-contained Adaptive Equalization and Sampling Point Control Using Stochastic Sigma-Tracking Eye-Opening Monitor

Abstract

This paper describes a 28-Gb/s receiver IC with self-contained adaptive equalization and sampling point control using an on-chip stochastic sigma-tracking eye-opening monitor (SSEOM). The proposed SSEOM accurately detects the bit-error-rate (BER)-related eye contour efficiently without the use of an external microcontroller. The SSEOM determines the BER-optimal sampling point and equalizer coefficients on the basis of pattern-filtered eye diagrams. It also features a background adaptation scheme for robust long-term operation by tracking temperature variations and device aging. The proposed SSEOM is integrated in a 28-Gb/s receiver that is designed to compensate for channel loss up to 25 dB at the Nyquist rate by using a continuous time linear equalizer (CTLE) and a one-tap decision feedback equalizer (DFE) together with an one-tap pre-emphasis at a transmitter. The time required for complete adaptation and the total power consumption are 364 ms and 43.9 mW, respectively. The proposed 28-Gb/s receiver is fabricated in 40 nm CMOS.