The LTC4284 negative voltage hot swap controller drives external N-channel MOSFETs to allow a board to be safely inserted and removed from a live backplane. The dual-gate, multi-mode drivers optimize the MOSFET safe operating area (SOA) for a variety of power levels. The SOA timer limits MOSFET temperature rise for reliable protection against overstresses.An I2C interface and onboard gear-shift ADC allow monitoring of board current, voltage, power, energy, and fault status. An available single-wire broadcast mode simplifies the interface by eliminating two isolators. The included EEPROM provides black-box capturing and nonvolatile configuration of fault behavior.Additional features respond to input UV/OV, interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a board, turn off the MOSFETs if an external supply monitor fails to indicate power good within a timeout period, and auto-reboot after a programmable delay following a host commanded turn-off.APPLICATIONSTelecom Infrastructure–48V Distributed Power SystemsServers and Data CentersPower Monitors