A transmit driver or transmitter is provided to generate an output data signal based on different input modes, such as low speed (LS), full speed (FS), high speed (HS), and high speed interconnect (HSIC) modes of a Universal Serial Bus (USB) standard. The transmit driver includes a rail voltage generator for generating a rail voltage for a set of transmit driver slices based on the selected mode. The transmit driver includes a bias voltage generator for generating a bias voltage based on the selected mode for protecting transistors in the transmit driver slices from over-voltage stress. The transmit driver includes a predriver and level shifter for generating input signals for the transmit driver slices to set the output impedance of the transmit driver and the slew rate of the output data signal. The transmit driver includes an emphasis equalizer for providing controllable emphasis equalization to the output data signal.