APPLICATIONS
? -48V Hot Swap Power Backplane/Distribution Central
Office, Ethernet for VOIP
? Positive Voltage Hotswap 12V to 60V Applications
(low side switching)
? Card Insertion Detection
? IP Phone Applications
? Databus Power Interfacing
? Custom Industrial Power Backplanes
? Distributed Power Systems
DESCRIPTION
The X80070 is a hot swap controller that allows a board to be
safely inserted and removed from a live backplane without
turning off the main power supply.
During insertion, the gate of an external power MOSFET is
clamped low to suppress contact bounce. The
undervoltage/overvoltage circuits and the power-on reset
circuitry suppress the gate turn on until the mechanical bounce
has ended. The X80070 turns on the gate with a slew rate to
limit the inrush current and incorporates an electronic circuit
breaker set by a sense resistor. After the load is successfully
charged, the PWRGD signal is asserted; indicating that the
device is ready to power sequence the DC-DC power bricks.
At all times, the X80070 monitors for undervoltage, overvoltage,
and overcurrent conditions. If any fault occurs, the gate will be
immediately shut off and the PWRGD will be returned to the
inactive state. The X80070 contains overvoltage, undervoltage
and overcurrent detection, hardshort retry, gate control slew
rate and power good control.