Novel direct-coupled current switch architecture for a series-connected voltage-balancing pulse driver

A series-connected voltage-balancing circuit can output n-times larger voltage swing than can be output by a single transistor, where n is the number of series-connected transistors. This circuit makes it possible for high-speed low-breakdown-voltage transistors to be applied to large-voltage-swing pulse drivers, such as an optical modulator driver. This paper reports the first operation of this type of driver at 10 Gbit/s. Novel direct-coupled current switch architecture prevents FETs exceeding gate-drain breakdown voltage and keeps high-speed operation. The fabricated driver demonstrated 3.7 V/sub pp/ (7.4 V/sub pp, diff/) output with clear eye opening.