Abstract: A differential transmitter uses an H-bridge driver with upper and lower current paths switched in opposite phases. Switching occurs at the lowest level of each column of the H-bridge driver, thereby allowing the use of thin-gate transistors for high speed. One or more transistors in each column are provided to assure consistent performance across a wide range of PVT variations, and to provide the required short-circuit, ESD, and latch-up protection. A scaled copy of a column of the H-bridge driver provides replica biasing to effect the required voltage shift from core to I/O voltage levels.