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ISL6144
Data Sheet
February 2004
FN9131
High Voltage ORing MOSFET Controller
The ISL6144 ORing MOSFET Controller and a suitably
sized N-channel power MOSFET(s) increases power
distribution efficiency and availability when replacing a
power ORing diode in high current applications.
In a multiple supply, fault tolerant, redundant power
distribution system, paralleled power supplies contribute
equally to the load current through various power sharing
schemes. Regardless of the scheme, a common design
practice is to include discrete ORing power diodes to protect
against reverse current flow should one of the power
supplies develop a catastrophic output short to ground. In
addition, reverse current can occur if the current sharing
scheme fails and an individual power supply voltage falls
significantly below the others.
Although the discrete ORing diode solution has been used
for some time and is inexpensive to implement, it has some
drawbacks. The primary downside is the increased power
dissipation loss in the ORing diodes as power requirements
for systems increase. Another disadvantage when using an
ORing diode would be failure to detect a shorted or open
ORing diode, jeopardizing power system reliability. An open
diode reduces the system to single point of failure while a
diode short might pose a hazard to technical personnel
servicing the system while unaware of this failure.
The ISL6144 can be used in 10V to 75V systems and has an
internal charge pump to provide a floating gate drive for the
N-channel ORing MOSFET. The High Speed (HS)
Comparator protects the common bus from individual power
supply shorts by turning off the shorted feed鈥檚 ORing
MOSFET in less than 300ns and ensuring low reverse
current.
An external resistor-programmable detection level for the HS
Comparator allows users to set the N-channel MOSFET
鈥淰OUT - VIN鈥?trip point to adjust control sensitivity to power
supply noise.
The Hysteretic Regulating (HR) Amplifier provides a slow
turn off of the ORing MOSFET. This turn off is achieved in
less than 100碌s when one of the sourcing power supplies is
shutdown slowly for system diagnostics, ensuring zero
reverse current. This slow turn off mechanism also reacts to
output voltage droop, degradation, or power down.
An open drain FAULT pin will indicate that a fault has
occurred. The fault detection circuitry covers different types
of failures; including dead short in the sourcing supply, a
short of any two ORing MOSFET terminals, or a blown fuse
in the power distribution path.
Features
鈥?Wide Supply Voltage Range +10V to +75V
鈥?Transient Rating to +100V
鈥?Reverse Current Fault Isolation
鈥?Internal Charge Pump allows the use of N-channel
MOSFET
鈥?HS Comparator Provides Very Fast <0.3碌s Response
Time to Dead Shorts on Sourcing Supply. HS Comparator
also has resistor-adjustable trip level
鈥?HR Amplifier allows Quiet, <100碌s MOSFET Turn Off for
Power Supply Slow Shut Down
鈥?Open Drain, Active Low Fault Output with 120碌s Delay
鈥?Provided in Packages Compliant to UL60950 (UL1950)
Creepage Requirements
鈥?QFN Package:
- Compliant to JEDEC PUB95 MO-220
QFN - Quad Flat No Leads - Package Outline
- Near Chip Scale Package footprint, which improves
PCB efficiency and has a thinner profile
鈥?Lead-Free Available as an Option
Applications
鈥?ORing MOSFET Control in Power Distribution Systems
鈥?N+1 Redundant Distributed Power Systems
鈥?File and Network Servers (12V and 48V)
鈥?Telecom/Datacom Systems
Ordering Information
PART #
ISL6144IV
ISL6144IVZA
(See Note)
ISL6144IR
ISL6144IRZA
(See Note)
TEMP. RANGE
(擄C)
-40 to +105
40 to +105
PACKAGE
16 Ld TSSOP
16 Ld TSSOP
(Lead-Free)
PKG. DWG. #
M16.173
M16.173
-40 to +105
-40 to +105
20 Ld 5x5 QFN L20.5x5
20 Ld 5x5 QFN L20.5x5
(Lead-Free)
NOTE: Intersil Lead-Free products employ special lead-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which is compatible with both SnPb
and lead-free soldering operations. Intersil Lead-Free products are
MSL classified at lead-free peak reflow temperatures that meet or
exceed the lead-free requirements of IPC/JEDEC J Std-020B.
Tape and Reel available. Add 鈥淭鈥?suffix for Tape and Reel Packing
Option.
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright 漏 Intersil Americas Inc. 2004. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
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