An Improved Low-Input Resistance Folded-Cascode Transimpedance Amplifier
for Giga-bit per second Optical Communication Front-Ends
Abstract
The present study is devoted to articulating a modified Folded-Cascode
circuit, to make Folded-Cascode structures an attractive configuration
as a Transimpedance Amplifier (TIA) for being employed in Giga-bit per
second optical communication receiver systems. Giga-bps communication
receivers are highly necessitating circuits to isolate the input
parasitic capacitance of the photodiode. The present modification makes
Folded Cascodes comparable to the famous Regulated Cascode (RGC)
structures by isolating this parasitic capacitor almost by the same
quantity. The system is shown to be capable of operating at 2.5Gbps up
to 8Gbps data rate with a fixed bandwidth. The paper analyzes and
evaluates the designed circuit mathematically, and the obtained
simulated results from Cadence using TSMC 65nm CMOS validate the
suitability of the modified circuit as a transimpedance amplifier.