The driver outputs are Hot Swap capable, maintaining backplane data integrity during board insertion and removal. The drivers feature three-state outputs, maintaining high impedance over the entire common mode range ( 7V to 12V). Outputs also remain high impedance during power-up and with the power off. A short-circuit feature detects bus contention and substantially reduces driver output current. Thermal shutdown circuitry protects the parts from excessive power dissipation. The LTC1688 allows all four drivers to be enabled together, while the LTC1689 allows two drivers at a time to be enabled.