The TPS2398 and TPS2399 integrated circuits are hot swap power managers optimized for use in nominal -48-V systems. For redundant-supply 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 singleexternal capacitor.