A source terminated transmission line driver circuit having an output coupled to a transmission line through a resistor is provided. The driver circuit has a gate circuit for providing first and second signals and a pulse generator circuit responsive to the second signal of the gate circuit for providing a pulse current at an output when the second signal is switching from a first logic state to a second logic state and for otherwise providing a quiescent current at the output. The driver circuit also has a first circuit responsive to the first output signal of the gate circuit for sourcing current to the output of the source terminated transmission line driver circuit, the first circuit being responsive to the second output signal of the gate circuit for sinking an adjustable current at the output of the source terminated transmission line driver circuit. The first circuit has a first transistor having a collector, a base and an emitter, the emitter being coupled to the output of the source terminated transmission line driver circuit, the base being coupled to receive the first signal of the gate circuit, and the collector being coupled to the first supply voltage terminal, a second transistor having a collector, a base and an emitter, the emitter of the second transistor being coupled to the output of the source terminated transmission line driver circuit, the base of the second transistor being coupled to the output of the pulse generator circuit, the collector being coupled to a second supply voltage terminal, a third transistor having a collector, a base and an emitter, the collector of the third transistor being coupled to the first supply voltage terminal, the base of the third transistor being coupled to the base of the first transistor, and a fourth transistor having a collector, a base and an emitter, the collector and base of the fourth transistor being coupled to the emitter of the third transitor, the emitter of the fourth transistor being coupled to the base of the second transistor.