The TPS2398 and TPS2399 integrated circuits are hot swap power managers optimized for use in nominal −48 V systems. They incorporate an improved circuit breaker response that provides rapid protection from short circuits, while still enabling plug−ins to tolerate large transients that can be generated by the sudden switchover to a higher voltage supply. They are designed for supply voltage ranges up to −80 V, and are rated to withstand spikes to −100 V. In conjunction with an external N−channel FET and sense resistor, they can be used to enable live insertion of plug−in cards and modules in powered systems. Both devices provide load current slew rate and peak magnitude limiting, easily programmed by sense resistor value and a single external capacitor.They also provide single-line fault reporting, electrical isolation of faulty cards, and protection against nuisance overcurrent trips. The TPS2398 latches off in response to current faults, while the TPS2399 periodically retries the load in the event of a fault.