A CMOS Low-Noise Fast-Settling BM-TIA with CM-Post-Amplifier Chip Connectivity for 50G-PON

With the bandwidth demand keeps growing, the next generation 50Gb/s Passive Optical Network (PON) is on the horizon. As the high-speed access network for most users, the increase in the cost of devices and modules makes low-cost components more desirable. Meanwhile, the multi-Km transmission distance and several layers of lossy optical splitter in PON dictate more sensitive receiver than those used in the datacenter. In the optical line termination (OLT) side, high-speed burst-mode (BM) transimpedance amplifiers (TIA) are mostly made by SiGe BiCMOS [1]–[3] to realize the harsh noise and settling time targets, with higher cost and large power consumption. Targeting on datacenter applications, some recent CMOS TIAs [4]–[5] have accomplished rapid BM settling through mixed-signal techniques. However, they can't be easily applied to BM-TIA for PON in the absence of clocking. Moreover, the post-amplifier chip that follows the BM-TIA needs also to be burst-mode amplifier, further complicating the system design with deteriorated performance and cost. In this paper, we address the noise and settling time challenges in the design of a 50-Gb/s CMOS BM-TIA for low cost, which also highlights its unique capability to drive a continuous-mode (CM) post-amplifier chip in BM application.