Design of a Novel CMOS Transimpedance Amplifier Based on a Current Mirror

ABSTRACT The transimpedance amplifier (TIA) is an essential component in optical communication systems. It converts the photodiode current to a voltage for further processing. In this paper, a novel CMOS current‐mirror‐based TIA is proposed. Its suitability to optical communication systems is verified. The current‐mirror topology is chosen due to its low input resistance and highly linear current amplification. The proposed TIA employs negative feedback and shunt‐inductive peaking to extend the bandwidth. Three configurations of the shunt‐inductive peaking are explored: one with passive inductors and two with active inductors. The proposed TIA is verified by simulation using the 45‐nm CMOS technology with a 1‐V supply and 1‐pF photodiode capacitance with the key performance trade‐offs discussed. A figure of merit ( FoM ) is introduced to evaluate the performance of the proposed TIA. The simulation results of the proposed TIA with passive inductors show a gain of 30.6 dB, a 3‐dB bandwidth of 2.8 GHz, and a power consumption of 1.63 mW, with an input‐referred noise current of 23.55 pA/√Hz.