The MAX5079 ORing MOSFET controller replaces
ORing diodes in high-reliability redundant, parallel-connected
power supplies. Despite their low forward-voltage
drop, ORing Schottky diodes cause excessive
power dissipation at high currents. The MAX5079
allows for the use of low-on-resistance n-channel power
MOSFETs to replace the Schottky diodes. This results
in low power dissipation, smaller size, and elimination
of heatsinks in high-power applications.
The MAX5079 operates from 2.75V to 13.2V and includes
a charge pump to drive the high-side n-channel MOSFET.
Operation down to 1V is possible if an auxiliary voltage of
at least 2.75V is available. When the controller detects a
positive voltage difference between IN and BUS, the
n-channel MOSFET is turned on. The MOSFET is turned
off as soon as the MAX5079 sees a negative potential at
IN with respect to the BUS voltage, and is automatically
turned back on when the positive potential is restored.
Under fault conditions, the ORing MOSFET's gate is
pulled down with a 1A current, providing an ultra-fast
200ns turn-off. The reverse voltage turn-off threshold is
externally adjustable to avoid unintentional turn-off of the
ORing MOSFET due to glitches at IN or BUS caused by
hot plugging the power supply.
Additional features include an OVP flag to facilitate
shutdown of a failed power supply due to an overvoltage
condition, and a PGOOD signal that indicates if VIN
is either below the undervoltage lockout or VBUS is in
an overvoltage condition. The MAX5079 operates over
the -40°C to +85°C temperature range and is available
in a space-saving 14-pin TSSOP package.
Key Features
Applications/Uses
2.75V to 13.2V Input ORing Voltage
1V to 13.2V Input ORing Voltage with 2.75V Aux
Voltage Present
2A MOSFET Gate Pulldown Current During Fault
Condition
Ultra-Fast 200ns, MOSFET Turn-Off During Fault
Condition
Supply Undervoltage and Bus Overvoltage
Detection
Power-Good (PGOOD) and Overvoltage (OVP)
Outputs for Fault Detection
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.
Devices:
1-4
of
4
MAX5079
Free Sample
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Package:
TYPE PINS FOOTPRINT
DRAWING CODE/VAR *
Temp
RoHS/Lead-Free? Materials Analysis
MAX5079EUD
TSSOP;14 pin;
Dwg: 21-0066 (PDF)
Use pkgcode/variation: U14-2*
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