Constant-bandwidth adaptive transimpedance amplifier

A new CMOS transimpedance amplifier (TIA) with variable gain for optical fibre communication receivers is presented. The proposed configuration is realised in a low-cost digital 0.35 mu m CMOS process fed from a single 1.8 V voltage supply. A 56-68 dB Omega transimpedance gain variation range is attained with 1 GHz bandwidth. The TIA shows 9 pA/root Hz input-referred spectral noise and only 6.9 mW power consumption.