
Freescale Semiconductor
2.0 A Negative Voltage Hot Swap Controller with Enhanced Programmability
The 34652 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.
FEATUREs
• Integrated Power MOSFET and Control IC in a Small Outline Package
• Input Voltage Operation Range from -15 V to -80 V
• Programmable Overcurrent Limit with Auto Retry
• Programmable Charging Current Limit Independent of Load Capacitor
• Programmable Start-Up and Retry Delay Timer
• Programmable Overvoltage and Undervoltage Detection
• Active High and Low Power Good Output Signals
• Thermal Shutdown
• Pb-Free Packaging Designated by Suffix Code EF