High power and high speed InP DHBT driver IC's for laser modulation

A driver IC and a 2:1 selector-driver IC developed for lightwave modulators are presented. The IC's were fabricated in a standard InP/InGaAs double heterojunction bipolar transistor technology with 56 GHz F t and 43 GHz F max. The driver operates up to 20 Gb/s with an output voltage swing of 4 V pp (corresponding to an internal current swing of 120 mA). The 2:1 selector-driver exhibits an output voltage swing of 2.2 V pp at 30 Gb/s. Specific design and layout aspects of such circuits are discussed.