Low-power, differential optical receiver in silicon on insulator

Abstract

A low-power differential optical receiver useful for high-speed optical communication between CMOS chips includes a multi-stage differential amplifier circuit including a first differential transimpedance stage ( ) followed by a plurality of differential feed-forward, high-bandwidth gain stages ( ) and a final, differential-to-single-ended converter output stage ( ). The inputs of the transimpedance stage receive input signals from a MSM or PIN diode photo-detector. Transistors having plural, different threshold levels are employed within each differential amplifier stage to reduce the size of the footprint of the circuit and improve the gain and bandwidth while decreasing the parasitic capacitance. The optical receiver is fabricated on a silicon on insulator chip, such as in an ultra-thin silicon on sapphire CMOS process which enables the design of high speed circuits with low power consumption and no substrate cross-talk. The circuit design is well-suited for use in a multi-dimensional array of optical interconnects between CMOS chips or platforms.