A fully differential CMOS transimpedance amplifier for optical receiver

Abstract

In this paper, a CMOS differential transimpedance amplifier is presented. The basic amplifier employs fT doubler and compensation capacitor techniques to enhance the bandwidth. The shunt-shunt feedback configuration is used to compromise between the wide bandwidth of the low impedance design and the low noise performance of the high impedance design. The phantom zero introduced by the feedback network is used to position the pole of the closed-loop system. HSPICE is used to verify the circuit performance with a 0.5 μm CMOS technology and a supply voltage of 2.5 V. Simulation results show the gain and -3 dB bandwidth of 80 dB and 2.4 GHz respectively. The equivalent input noise current is less than 18.4 pA/√Hz within the amplifier frequency band and the total power dissipation is 23 mW.