The MC34672 is a highly integrated - 48 V hot swap controller with an internal Power MOSFET. It provides the means to safely install and remove boards from live - 48 V backplanes without having to power down the entire system. It regulates the inrush current, from the supply to the load’s filter capacitor, to a user-programmable limit, allowing the system to safely stabilize. A disable function allows the user to disable the 34652 manually or through a microprocessor and safely disconnect the load from the main power line.
The 34652 has active high and active low power good output signals that can be used to directly enable a power module load. Programmable under- and overvoltage detection circuitry monitors the input voltage to check that it is within its operating range. A programmable start-up delay timer ensures that it is safe to turn on the Power MOSFET and charge the load capacitor.
A two-level current limit approach to controlling the inrush current and switching on the load limits the peak power dissipation in the Power MOSFET. Both current limits are user programmable.