JSSC 2019第8期RF & Wireless45nm

A Differential Optical Receiver With Monolithic Split-Microring Photodetector

提出一种采用新型谐振分裂微环光电探测器的高灵敏度全差分光接收器，用于高密度片上系统应用。

45nm SOI CMOS, 0.52-A/W responsivity, 5.0 GHz bandwidth, BER < 10−12 at 12 Gb/s, −18.2 dBm OMA sensitivity, 7 mW power consumption

光接收器全差分分裂微环光电探测器高灵敏度片上系统

▸使用新型谐振分裂微环光电探测器实现全差分操作

▸抑制共模和电源噪声，提高接收器灵敏度

▸在45nm SOI CMOS工艺中实现，无需工艺变更

Abstract

This paper presents a high-sensitivity, fully dif- ferential (FD) optical receiver (RX) for high-density system- on-chip applications. The high digital activity prominent in such applications creates common-mode and power-supply noise, which degrades the optical RX sensitivity. To suppress these noise sources and enhance the RX sensitivity, an optical RX is proposed that realizes FD operation by using a new resonant split-microring photodetector. The complete RX is implemented in a 45-nm SOI CMOS with no process changes. When aptly biased, the detector outputs FD photocurrent with <±0.3% splitting error. It has 0.52-A/W responsivity and a bandwidth of 5.0 GHz. The RX circuit is optimized to achieve BER < 10 −12 at 12 Gb/s with an optical modulation amplitude (OMA) sensitivity of −18.2 dBm while consuming 7 mW. Compared with a conventional single-ended RX on the same test-chip, the proposed RX improves sensitivity from 13 to 7.9 µA pp without reducing the bandwidth or signiﬁcantly impacting the RX energy efﬁciency.