Output driver circuit having adjustable swing width, method of adjusting a swing width of an output signal, and high speed input circuit

An output driver is responsive to an input signal and a swing width control signal (TE). The output driver is configured to generate an output signal having a first swing width (e.g., less than rail-to-rail) when the swing width control signal designates a normal mode of operation and a second swing width (e.g., rail-to-rail) when the swing width control signal designates a test mode of operation.