Features allow insertion and removal of control supply voltages from 10.8V to 36V from a live BSA
Foldback Current-Limited Open Circuit and Overcurrent Fault Detection Drives an External N-Channel MOSFET
Automatically retry or shut down operation Lockout after overcurrent fault Programmable supply voltage

Application Hot Plate Insertion Electronic Circuit Breaker / Power Bussing
Industrial high-end switches/circuit breakers
24V Industrial/Alarm System
12V and 24V distributed power system

The LT®4254 is a high voltage thermal SwapTM controller that allows boards to be safely inserted and removed from a live backplane. An internal driver controls the gate voltage of the high-side N-channel MOSFET from the supply 10.8V to 36V. Output of partial function open circuit detection (open), indicating abnormally low load current condition. The LT4254 features an adjustable analog foldback current limit. If the supply remains within the current limit for more than a programmable time, the N-channel MOSFET turns off, the PWRGD output goes low, and the LT4254 either restarts automatically after a time-out delay or latches off until the UV pin cycles low. Retry if the socket part will automatically restart after an overcurrent fault or if it will latch up until the UV pin is low cycled. The PWRGD output indicates when the output voltage rises above a set level. An external resistor from the VCC string provides programmable undervoltage and overvoltage protection.