A 10-Gb/s Optical Receiver with Sub-Microampere Input-Referred Noise

High-speed optical receivers realized in low-cost technology often suffer from unfavorable performance, dictated by the transimpedance limit, the key design constraint of shunt-shunt feedback transimpedance amplifier (TIA). In this letter, we propose a novel TIA architecture to overcome the transimpedance limit, achieving both low noise and high gain that are not realizable in a conventional topology. A 10-Gb/s optical receiver with sub-microampere input-referred noise current is implemented in a mature 0.18- $\mu \text{m}$ CMOS technology. Wire-bonded with a commercial III-V p-i-n photodiode, the receiver demonstrates the state-of-the-art input-referred noise current of 0.97 $\mu $ Arms and a total transimpedance gain of 68.3 dB $\Omega $ while consuming 45 mA from 1.8-V power supply. Finally, the proposed architecture is applicable to 10 Gb/s beyond to realize low-noise high-gain optical receivers.