Design of a 2.5 Gbps CMOS trans-impedance amplifier (TIA) for optical communication

A wide band CMOS trans-impedance amplifier (TIA) was designed for optical receiver application. This amplifier implemented in a 0.25-/spl mu/m digital CMOS process can be characterized with a transimpedance gain of 55.9 dB/spl Omega/ at 2.08 GHz -3 dB bandwidth, while dissipating 18.75 mW with 2.5 V supply. The bandwidth can be extended by inductive peaking technique using active inductor and trans-conductance (gm) enhancement technique. In single-ended stage, the TIA without buffer in feedback path provides good loop gain and higher input and output resistances in comparison with the TIA with buffer in feedback path. The core circuit of the designed TIA occupies a chip area of 46 /spl mu/m /spl times/ 50 /spl mu/m only.