A design methodology for low-noise CMOS transimpedance amplifiers based on shunt-shunt feedback topology

The regulated cascode (RGC) is a widely used topology in transimpedance amplifiers projects. Although it is efficient with respect to power consumption and bandwidth, the regulated cascode presents high input-referred current noise levels that hinder the use of this topology in long distance optical networks. In this paper is proposed a design methodology for CMOS transimpedance amplifiers based on shunt-shunt feedback topology to achieve a broad-band response with low input referred current noise. A complete analysis of the shunt-shunt amplifier is presented. Experimental results shown a 51 dBΩ transimpedance gain and a 10.54GHz bandwidth. The achieved average input referred current noise equals to 6.8 pA/√(Hz), the lowest one between other state-of-art CMOS designs. The circuit was manufactured in 130 nm RF CMOS technology.