High-gain SiGe transimpedance amplifier array for a 12×10 Gb/s parallel optical-fiber link

A transimpedance amplifier array for 12 parallel optical-fiber channels each operating at 10 Gb/s is presented, which is used in the receiver of short-distance links. It stands out for the following features: high gain (transimpedance 25 kΩ in the limiting mode), high input sensitivity and wide input dynamic range (input current swing from 20 to 240 μA_p-p), constant output voltage swing (differential 0.5 V_p-p at 50 Ω load), and low power consumption (1.4 W) at a single supply voltage (5 V). Each channel has its own offset-current control circuit. To the best of the authors´ knowledge, the total throughput of 12×10 Gb/s=120 Gb/s is the highest value reported for a single-chip amplifier array. The target specifications have been achieved with the first technological run without needing any redesign. This fact demonstrates that the inherent severe crosstalk problems of such high-gain amplifier arrays can reliably be solved by applying adequate decoupling measures and simulation tools.