DATASHEET
ISL6144
FN9131
Rev 7.00
High Voltage ORing MOSFET Controller
October 6, 2011
The ISL6144 ORing MOSFET Controller and a suitably sized
Features
N-Channel power MOSFET(s) increases power distribution
Wide Supply Voltage Range +9V to +75V
efficiency and availability when replacing a power ORing diode
in high current applications.
Transient Rating to +100V
In a multiple supply, fault tolerant, redundant power distribution Reverse Current Fault Isolation
system, paralleled similar power supplies contribute equally to
Internal Charge Pump Allows the use of N-Channel
the load current through various power sharing schemes.
MOSFET
Regardless of the scheme, a common design practice is to
HS Comparator Provides Very Fast <0.3s Response
include discrete ORing power diodes to protect against reverse
Time to Dead Shorts on Sourcing Supply. HS Comparator
current flow should one of the power supplies develop a
also has Resistor-adjustable Trip Level
catastrophic output short to ground. In addition, reverse current
can occur if the current sharing scheme fails and an individual HR Amplifier allows Quiet, <100s MOSFET Turn-off for
Power Supply Slow Shut Down
power supply voltage falls significantly below the others.
Open Drain, Active Low Fault Output with 120s Delay
Although the discrete ORing diode solution has been used for
some time and is inexpensive to implement, it has some
Provided in Packages Compliant to UL60950 (UL1950)
drawbacks. The primary downside is the increased power
Creepage Requirements
dissipation loss in the ORing diodes as power requirements for
QFN Package:
systems increase. Another disadvantage when using an ORing
- Compliant to JEDEC PUB95 MO-220
diode would be failure to detect a shorted or open ORing diode,
QFN - Quad Flat No Leads - Package Outline
jeopardizing power system reliability. An open diode reduces
- Near Chip Scale Package footprint, which improves
the system to single point of failure while a diode short might
PCB efficiency and has a thinner profile
pose a hazard to technical personnel servicing the system
while unaware of this failure. Pb-Free (RoHS Compliant)
The ISL6144 can be used in 9V to 75V systems having similar
Applications
power sources and has an internal charge pump to provide a
ORing MOSFET Control in Power Distribution Systems
floating gate drive for the N-Channel ORing MOSFET. The High
Speed (HS) Comparator protects the common bus from
N + 1 Redundant Distributed Power Systems
individual power supply shorts by turning off the shorted feeds
File and Network Servers (12V and 48V)
ORing MOSFET in less than 300ns and ensuring low reverse
current.
Telecom/Datacom Systems
An external resistor-programmable detection level for the HS
Comparator allows users to set the N-Channel MOSFET
V - V trip point to adjust control sensitivity to power
OUT IN
supply noise.
The Hysteretic Regulating (HR) Amplifier provides a slow turn-
off of the ORing MOSFET. This turn-off is achieved in less than
100s 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.
FN9131 Rev 7.00 Page 1 of 30
October 6, 2011ISL6144
Ordering Information
PART NUMBER PART TEMP. RANGE PACKAGE PKG.
(Notes 2, 3) MARKING (C) (Pb-free) DWG. #
ISL6144IVZA (Note 1) ISL61 44IVZ -40 to +105 16 Ld TSSOP M16.173
ISL6144IRZA (Note 1) ISL6144 IRZ -40 to +105 20 Ld 5x5 QFN L20.5x5
ISL6441EVAL1Z Evaluation Platform
NOTES:
1. Add -T* suffix for tape and reel. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin
plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see device information page for ISL6144. For more information on MSL please see techbrief TB363.
Pinouts
ISL6144 ISL6144
(16 LD TSSOP) (20 LD 5x5 QFN)
TOP VIEW TOP VIEW
GATE 1 16 VOUT
20 19 18 17 16
2 15
VIN COMP
1 15
VIN VOUT
3 14 VSET
HVREF
HVREF 2 14 COMP
4 13 NC
NC
NC 3 13 VSET
5 12 NC
NC
NC 4 12 NC
6 11
NC
NC
NC 5 11 NC
7 10 NC
NC
67 8 9 10
8 9 FAULT
GND
Pin Descriptions
TSSOP QFN
PIN # PIN # SYMBOL FUNCTION DESCRIPTION
1 19 GATE External FET Gate Drive Allows active control of external N-Channel FET gate to perform ORing function.
2 1 VIN Power Supply Connection Chip bias input. Also provides a sensing node for external FET control.
3 2 HVREF Chip High Voltage Reference Low side of floating high voltage reference for all of the HV chip circuitry.
8 7 GND Chip Ground Reference Chip ground reference point.
99 FAULT Fault Output Provides an open drain active low output as an indication that a fault has
occurred: GATE is OFF (GATE < V + 0.37V) or other types of faults
IN
resulting in V - V > 0.41V.
IN OUT
14 13 VSET Low Side Connection for Resistor connected to COMP provides adjustable Vd - Vs trip level along
Trip Level with pin COMP.
15 14 COMP High Side Connection for HS Resistor connected to V provides sense point for the adjustable Vd - Vs
OUT
Comparator Trip Level trip level along with pin VSET.
16 15 VOUT Chip Bias and Load Provides the second sensing node for external FET control and chip output
Connection bias.
4, 5, 6, 7, 3, 4, 5, 6, 8, NC No Connection
10, 11, 10, 11, 12,
12, 13 16, 17,
18, 20
FN9131 Rev 7.00 Page 2 of 30
October 6, 2011
NC NC
GND GATE
NC NC
FAULT NC
NC NC