The LTC4214 negative voltage Hot Swap™controller allows a board to be safely inserted and removed from a live backplane. Output current is controlled by three stages of current limiting: a timed circuit breaker, active current limiting and a fast feedforward path that limits peak current under worst-case catastrophic fault conditions.Adjustable undervoltage and overvoltage detectors disconnect the load whenever the input supply exceeds the desired operating range. The LTC4214 controls negative supplies ranging from near zero to –16V. A multifunction timer delays initial start-up and controls the circuit breaker’s response time. This response time is accelerated by sensing excessive MOSFET drain voltage, keeping the MOSFET within its safe operating area (SOA). An adjustable soft-start circuit controls MOSFET inrush current at start-up. A power good status output can enable a power module at start-up or disable it if the circuit breaker trips.The LTC4214-1 latches off after a circuit breaker fault times out. The LTC4214-2 provides automatic retry after a fault. The LTC4214 is available in the 10-pin MSOP package.ApplicationsHot Board InsertionElectronic Circuit BreakerNegative Power Supply ControlCentral Office SwitchingHigh Availability ServersDisk ArraysOptical Networking/SwitchingECL