Low noise current-mode CMOS transimpedance amplifier for giga-bit optical communication

A novel current-mode CMOS transimpedance amplifier is described. The design uses a common-gate regulated cascode configuration providing low input impedance and low input current noise. HSPICE simulations using a 0.6 /spl mu/m CMOS process give 3.5 GHz bandwidth, 61 dB transimpedance gain, 4.2 pA//spl radic/(Hz) equivalent input noise current spectral density, and 135 mW power consumption. Measured results of a previous test chip are also presented.