An 80-Gb/s 2.7-Vp-p driver IC based on functional distributed circuits for optical transmission systems

A driver IC based on InP HBTs with a new circuit topology - called functional distributed circuit (FDC) - for over 40-Gb/s optical transmission systems has been developed. The FDC topology enables both wider bandwidth and digital functions. The distributed differential amplifier stage in the developed driver IC exhibits 2.4-V_p-p output voltage swings (differential output: 4.8 V_p-p) and good eye openings at 50 Gb/s. Integrated with a 2:1 selector, the driver IC produces 2.7-V_p-p output voltage swings (differential output: 5.4 V_p-p) with high signal quality at 80 Gb/s. This is equivalent to the highest data rate operation yet reported. These results indicate that the FDC has the potential to realize high-speed and functional ICs for over 40-Gb/s transmission systems.