What this TPS2398DGK hot swap controller does
It manages the inrush current when a line card is plugged into a live -48V rail, using an external N-channel MOSFET as the pass element — there is no internal switch. The controller integrates undervoltage lockout (UVLO) and latched fault protection, and gives you programmable control over current limit, fault timeout, and output slew rate via external components.
The supply range is -80V to -36V, which directly covers the standard -48V telecom nominal with healthy margin for transients. If your design lives in a temperature-controlled data center, that is still fine, but the part is not rated for under-hood automotive or downhole environments.
Programmable features and what they buy you
You can set the current limit, fault timeout, and output slew rate with external resistors and a capacitor. That means you can tailor the inrush profile to the bulk capacitance on your card — slow the slew rate for a large capacitor bank, or set a tight fault timeout to catch a short before the backplane breaker trips. The latched fault behavior means once a fault is detected, the controller shuts off and stays off until you cycle the power or the enable signal — no automatic retry, which is the safer choice for a -48V system where an auto-retry could hammer the backplane.
Package and mounting — field-service reality
It comes in an 8-VSSOP package (3.00 mm width), surface mount. That is a small outline, fine-pitch part — not something you swap in a parking lot with a soldering iron.
It is ROHS3 compliant.