An Integrated Burst-Mode 2R Receiver Employing Fast Residual Offset Canceller for XGS-PON in 40-nm CMOS.

The recent boom of XGS-PON (10Gb/s symmetrical passive optical network) mandates low cost the massive volume of the consumer market. Critically, the time-division multiplexing method in upstream PON demands burst-mode (BM) receiver (Rx) with minimum settling time so that each user can capture more effective bandwidth. The BM-Rx needs to execute the 3R functions of re-amplify (TIA), reshape (LA) and re-time (CDR) successively. Since the amplitude of the incoming burst signal can vary by more than 1000x from microampere to milliampere, offset cancellation which occurs in the first 2R function tends to be difficult. Made in SiGe BiCMOS, the conventional 2R BM-Rx not only suffer from excessive settling time and large power consumption [1-3], but also are expensive. Some recent CMOS BM-Rx [4], [5] have achieved fast settling through high-speed mixed-signal approaches, but their dynamic range, sensitivity and the need of external clocking are incompatible with current PON. In this paper, we present an integrated 2R BM-Rx with fast offset cancellation approaches to reduce the settling time significantly.