Bandwidth improvements in transimpedance amplifiers for visible-light receiver front-ends

Abstract

This paper analyzes a method for bandwidth improvement based on a gain-bandwidth boosting technique in transimpedance amplifiers. This method is suitable for visible light receiver front-ends employing large area photodiodes, where open loop voltage gain can be optimized according to the photodiode capacitance. Theoretical results, assuming a two-pole transfer function, are compared with simulation and measurement results, using the 350nm SiGe process from AMS. Achieved results show that using this approach it is possible to reach 50MHz of bandwidth and 10KΩ maximally flat transimpedance amplifier gain with a 50pF photodiode. Power consumption (10.2mW) and noise thermal floor (2pA/√Hz) were not significantly affected.