Linear Technology Corp. (LTC, Milpitas, CA) introduced the LT4254, a positive hot-swap controller that allows boards with supplies up to 36V to be safely inserted into a live backplane without risking damage to the connectors or causing glitches. The IC provides an open-circuit-detect output that can be used to indicate abnormally low-load current conditions or no load presence at all.
The LT4254 features an adjustable current limit that is programmable through a sense resistor. Foldback current limiting is provided to protect the external n-channel MOSFET. By controlling the supply voltage ramp-up rate, the LT4254 maintains inrush current to the board within safe levels. If the part remains in current limit for more than a pre-programmed time, the LT4254 shuts off the external n-channel MOSFET. The part then restarts automatically or latches off depending on the retry pin configuration.
The LT4254 is offered in a 16-lead SSOP package and is available in both the commercial and industrial temperature ranges. Pricing starts at $2.50 each for 1,000-piece quantities.
