The MAX5955 and MAX5956 are +1V to +13.2V dual hot-swap controllers with independent on/off control for complete protection of dual-supply systems. They allow the safe insertion and removal of circuit cards into live backplanes. The MAX5955 and MAX5956 operate down to 1V provided one of the inputs is above 2.7V. The discharged filter capacitors of the circuit card provide low impedance to the live backplane. High inrush currents from the backplane to the circuit card can burn up connectors and components, or momentarily collapse the backplane power supply leading to a system reset. The MAX5955 and MAX5956 hot-swap controllers prevent such problems by gradually ramping up the output voltage and regulating the current to a preset limit when the board is plugged in, allowing the system to stabilize safely. After the startup cycle is completed, two on-chip comparators provide VariableSpeed/BiLevelTM protection against short-circuit and overcurrent faults, as well as immunity against system noise and load transients. In the event of a fault condition, the load is disconnected. The MAX5955B and MAX5956B must be unlatched after a fault, and the MAX5955A and MAX5956A automatically restart after a fault.