The LT4250L/LT4250H are 8-pin, negative 48V Hot Swap™ controllers that allow a board to be safely inserted and removed from a live backplane. Inrush current is limited to a programmable value by controlling the gate voltage of an external N-channel pass transistor. The pass transistor is turned off if the input voltage is less than the programmable undervoltage threshold or greater than the overvoltage threshold. A programmable current limit protects the system against shorts. After a 500μs timeout the current limit activates the electronic circuit breaker. The PWRGD (LT4250L) or PWRGD (LT4250H) signal can be used to directly enable a power module. The LT4250L is designed for modules with a low enable input and the LT4250H for modules with a high enable input. The LT4250L/LT4250H are available in 8-pin PDIP and SO packages Applications * Central Office Switching * –48V Distributed Power Systems * Negative Power Supply Control * Allows Safe Board Insertion and Removal from a Live –48V Backplane * Circuit Breaker Immunity to Voltage Steps and Current Spikes * Programmable Inrush and Short-Circuit Current Limits * Pin Compatible with LT1640L/LT1640H * Operates from –18V to –80V * Programmable Overvoltage Protection * Programmable Undervoltage Lockout * Power Good Control Output * Bell-Core Compatible ON/OFF Threshold https://elecena.pl/product/1021538/negative-48v-hot-swap-controller 2010-02-11 https://elecena.pl/product/1021538/negative-48v-hot-swap-controller 2014-04-19 https://elecena.pl/product/1021538/negative-48v-hot-swap-controller 2025-01-22