High power modulator driver ICs up to 30 Gb/s with AlGaAs/GaAs HEMTs

Abstract

Two monolithic integrated transmitter circuits of a modulator driver and a modulator driver with a 2:1 multiplexer for high-speed optical-fiber links are presented. The ICs featuring differential configuration were fabricated in a 0.2 /spl mu/m gate-length enhancement and depletion HEMT technology with 60 GHz and 55 GHz f/sub T/. The modulator driver operates up to 25 Gb/s with an output voltage swing of 3.3 V/sub p-p/ at each output (corresponding to an internal current swing of 100 mA). The total voltage gain is 22 dB. The modulator driver with a integrated 2:1 multiplexer performs a data rate up to 30 Gb/s with an output voltage swing of 2.2 V/sub p-p/ at each output. Each circuit consumes 1.4 W power using a single supply voltage of -5 V.