In one embodiment, a transmission line pre-emphasis circuit includes a primary signal path generating a primary differential output current indicative of a digital data stream and a secondary signal path including a pulse shaping stage incorporating a network and a scaling stage. The pre-emphasis circuit generates an overshoot pulse with variable pulse width. In another embodiment, a transmission line pre-emphasis circuit includes a primary signal path generating a primary differential output current indicative of a digital data stream and one or more secondary signal paths incorporating a network implementing a specific transient response. Each of the secondary signal paths includes a scaling stage and a shaping stage each with programmable bias current. The scaling stage can be configured before or after the shaping amplifier. The pre-emphasis circuit generates an overshoot signal with variable amplitude and/or variable width.