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LT4351CMS#TRPBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
LT4351
1
4351fd
TYPICAL APPLICATION
DESCRIPTION
MOSFET Diode-OR
Controller
The LT
®
4351 creates a near ideal diode using external
single or back-to-back N-channel MOSFETs. This ideal
diode function permits low loss ORing of multiple power
sources. Power sources can easily be ORed together to
increase total system power and reliability with minimal
effect on supply voltage or efficiency. Disparate power
supplies can be efficiently ORed together.
The IC monitors the input supply with respect to the load
and turns on the MOSFET(s) when the input supply is
higher. If the MOSFET’s R
DS(ON)
is sufficiently small, the
LT4351 will regulate the voltage across the MOSFET(s)
to 15mV. A STATUS pin indicates the MOSFET on-state.
An internal boost regulator generates the MOSFET gate
drive voltage. Low operating voltage allows for ORing of
supplies as low as 1.2V.
The LT4351 will disable power passage during undervolt-
age or overvoltage conditions. These voltages are set by
resistive dividers on the UV and OV pins. The undervoltage
threshold has user programmable hysteresis. Overvoltage
detection is filtered to reduce false triggering.
The LT4351 is available in a 10-pin MSOP package.
Dual 5V Redundant Supply
FEATURES
APPLICATIONS
n
Low Loss Replacement for ORing Diode in Multiple
Sourced Power Supplies
n
External N-Channel MOSFETs for High Current
Capability
n
Internal Boost Regulator Supply for MOSFET
Gate Drive
n
Wide Input Range: 1.2V to 18V
n
Fast Switching MOSFET Gate Control
n
Input Under and Overvoltage Detection
n
STATUS and FAULT Outputs for Monitoring
n
Internal MOSFET Gate Clamp
n
Available in a 10-pin MSOP Package
n
Paralleled Power Supplies
n
Uninterrupted Supplies
n
High Availability Systems
n
N + 1 Redundant Power Supplies
LOADC
LOAD
GATE OUTV
IN
V
DD
SW
LT4351
UV
OV
STATUS
1µF
24.9k
1%
232Ω
1%
1.47k
1%
10µF
5V
POWER
SUPPLY
1
4.7µH
MBR0530
MBR0530
FAULT
GND
Si4862DYSi4862DY
1× 1×
GATEOUT
5V COMMON
V
IN
V
DD
SW
LT4351
UV
OV
4351 TA01
GND
POWER
SUPPLY
2
1µF
24.9k
1%
232Ω
1%
1.47k
1%
10µF
5V
4.7µH
MBR0530
MBR0530
STATUS
FAULT
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
LT4351
2
4351fd
PIN CONFIGURATIONABSOLUTE MAXIMUM RATINGS
V
IN
Voltage ................................................ –0.3V to 19V
OUT Voltage
............................................. –0.3V to 19V
V
DD
Voltage .............................................. –0.3V to 30V
FAULT, STATUS Voltages
.......................... –0.3V to 30V
FAULT, STATUS Current
.......................................... 8mA
UV, OV Voltages
......................................... –0.3V to 9V
SW Voltage
.............................................. –0.3V to 32V
Operating Temperature Range
LT4351C .................................................. 0°C to 70°C
LT4351I ............................................... –40°C to 85°C
Junction Temperature (Note 2)
............................ 125°C
Storage Temperature Range
.................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
.................. 300°C
(Note 1)
1
2
3
4
5
GATE
V
DD
V
IN
SW
GND
10
9
8
7
6
OUT
STATUS
FAULT
UV
OV
TOP VIEW
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 125°C, θ
JA
= 120°C/W
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LT4351CMS#PBF LT4351CMS#TRPBF LTZZ 10-Lead Plastic MSOP 0°C to 70°C
LT4351IMS#PBF LT4351IMS#TRPBF LTA 1 10-Lead Plastic MSOP –40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Supply and Protection
V
IN
Operating Range
l
1.2 18 V
I
VIN
V
IN
Supply Current V
IN
= 1.2V, V
OUT
= 1.1V, V
DD
= 12.3V
V
IN
= 18V, V
OUT
= 17.9V, V
DD
= 29.1V
l
l
1.41
1.71
2
2.1
mA
mA
V
UV(TH)
Undervoltage Turn-Off Voltage
Threshold
UV Falling
l
290 300 310 mV
I
UV(HYST)
I
UV
Hysteresis Difference Between I
UV
at V
UV(TH)
+ 10mV and
V
UV(TH)
– 10mV
l
7 10 13 µA
I
UV
UV Input Bias Current V
UV
= V
UV(TH)
+ 10mV
l
–100 –400 nA
V
OV(TH)
Overvoltage Threshold OV Rising
l
290 300 310 mV
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= V
OUT
= 5V, V
DD
= 16.1V, V
UV
= 0.4V, V
OV
= 0.2V, GATE Open, unless
otherwise specified.
LT4351
3
4351fd
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= V
OUT
= 5V, V
DD
= 16.1V, V
UV
= 0.4V, V
OV
= 0.2V, GATE Open, unless
otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
OV
OV Input Bias Current V
OV
= V
OV(TH)
– 10mV
l
–100 –400 V
V
F(ON)
FAULT Pin On-Voltage I
F
= 5mA in Fault Condition
l
0.14 0.25 V
I
F(OFF)
FAULT Pin Leakage Current V
F
= 30V, V
IN
= 4.9V
l
0.04 1 µA
Boost Supply
V
BR
Boost Regulation Trip Voltage Measured as V
DD
to V
IN
, Rising Edge
l
10.2 10.7 11.4 V
t
OFF
Boost Supply Off-Time 600 ns
I
SWLIM
Boost Supply Switch Current Limit
l
350 450 650 mA
Gate Drive
V
IOR
Input-to-Output Regulated Voltage
l
4 15 25 mV
∆V
GL
Gate Voltage Limit V
IN
= 5V, V
OUT
= 4.9V, V
DD
= 13V Measured with
Respect to V
DD
l
–2.3 –3 V
∆V
G(MAX)
Maximum Gate Voltage V
IN
= 5V, V
OUT
= 4.9V, V
DD
= 16.1V Measured with
Respect to V
OUT
l
7 7.4 7.8 V
V
G(OFF)
Gate Off-Voltage V
OUT
= 5.1V
l
0.16 0.30 V
I
GSO
Gate Source Current V
OUT
= 4.9V, V
GATE
= 9V 0.670 A
I
GSK
Gate Sink Current V
OUT
= 5.1V, V
GATE
= 9V 0.670 A
V
DD
Operating Range
l
30 V
I
VDD
V
DD
Supply Current V
IN
= 1.2V, V
OUT
= 1.1V, V
DD
= 12.3V, GATE Open
V
IN
= 18V, V
OUT
= 17.9V, V
DD
= 29.1V, GATE Open
l
l
3
3.6
4
5.6
mA
mA
Status Functions
∆V
GIS
Minimum Gate Voltage for Turning
On Status
V
OUT
= 4.9V, I
STATUS
= 1mA
l
0.75 1 V
V
IOGF
V
IN
to V
OUT
Fault Voltage with
Open Gate
V
OUT
Falling, Measured with Respect to V
IN
185 210 230 mV
V
ST(ON)
Status Pin On-Voltage I
ST
= 5mA, V
OUT
= 4.9V, Status On
l
0.13 0.25 V
I
ST(OFF)
Status Pin Leakage Current V
ST
= 30V, Status Off, V
IN
= 4.9V
l
0.04 1 µA
Note 2: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
T
J
= T
A
+ (P
D
• 120°C/W)
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20

LT4351CMS#TRPBF

Mfr. #:
Buy LT4351CMS#TRPBF
Manufacturer:
Analog Devices Inc.
Description:
Power Management Specialized - PMIC MOSFET Diode-OR Cntr
Lifecycle:
New from this manufacturer.
Delivery:
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