The present invention relates to a programmable low-voltage differential
signaling (LVDS) output driver. The programmable LVDS output driver may
include circuitry for tri-stating the output to allow several
programmable LVDS output drivers to be coupled to a single receiver. The
programmable LVDS output driver may also include programmable current
sources for varying the output current, as well as providing additional
current to circuitry within the driver (e.g., impedance circuitry). The
programmable LVDS output driver may also include an impedance circuit for
adjusting the output impedance of the output driver, while only diverting
a small amount of source current. The current diverted by the impedance
circuit may be compensated for by increasing the source current from the
programmable current sources. The programmable LVDS output driver may
also include pre-emphasis circuitry for boosting the edge rates of output
signals.