A 30 Gb/s High-Swing, Open-Collector Modulator Driver in 250 nm SiGe BiCMOS

This paper presents a modulator driver realized as a breakdown voltage doubler which can provide a high output swing of 7.6 Vpp,diff for load impedances as low as 30 Ω, thus overcoming the limitation imposed by the collector-emitter breakdown voltage. The open-collector design gives an important degree of freedom regarding the modulator load to be driven, while significantly reducing the circuit's power consumption. The driver is capable of running at 30 Gb/s while dissipating 1 W of DC power. Thanks to the inductorless design, the active area occupied by the circuit is only 0.28 mm × 0.23 mm. The driver was realized in a 250 nm SiGe BiCMOS technology.