A highly sensitive 2.5 Gb/s transimpedance amplifier in CMOS technology

This paper presents a new transimpedance amplifier (TIA) for 2.5 Gbit/s optical communications realized in a standard 90 nm CMOS process. The proposed TIA is based on a conventional structure with an inverting voltage amplifier and a feedback resistor, but incorporates a new technique to enhance the input dynamic range and to prevent the TIA saturation at high input currents. Post-layout results show an optical sensitivity of -30 dBm for a BER=10^-12 and a maximum input current of 1 mA_pp, what leads to an optical power dynamic range above 27 dB. The power consumption of the TIA is only 4.3 mW at a single supply voltage of 1 V.