A CMOS variable-gain transimpedance amplifier for infrared wireless data communications

A CMOS infrared wireless optical receiver front-end is presented. A stable variable-gain fully differential transimpedance feedback amplifier is designed employing a current-mode amplifier as the feedforward gain element. For a more than three times variation of the transimpedance gain, from 0.3 k/spl Omega/ to 1 k/spl Omega/, the variable-gain transimpedance amplifier achieves desirable gain-bandwidth independence.