FEATURES
s s s s s s DESCRIPTIO s s s Allows Safe Board Insertion and Removal from a Live Backplane Controls Supply Voltage from 10.8V to 36V Foldback Current Limiting Open Circuit and Overcurrent Fault Detect Drives an External N-Channel MOSFET Automatic Retry or Latched Off Operation After Overcurrent Fault Programmable Supply Voltage Power-Up Rate Undervoltage and Overvoltage Protection Open MOSFET Detection The LT®4254 is a high voltage Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. An internal driver controls the high side N-channel MOSFET gate for supply voltages ranging from 10.8V to 36V. The part features an open-circuit detect (OPEN) output that indicates abnormally low load current conditions. If the supply remains in current limit for more than a programmable time, the N-channel MOSFET shuts off, the PWRGD output goes low and the LT4254 either automatically restarts after a time-out delay or latches off until the UV pin is cycled low.