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Diode-OR Controller. LT4351 Datasheet

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Diode-OR Controller. LT4351 Datasheet






LT4351 Controller. Datasheet pdf. Equivalent




LT4351 Controller. Datasheet pdf. Equivalent





Part

LT4351

Description

MOSFET Diode-OR Controller



Feature


( DataSheet : www.DataSheet4U.com ) LT4 351 MOSFET Diode-OR Controller FEATURE S s s DESCRIPTIO s s s s s s s Low Loss Replacement for ORing Diode in Mul tiple Sourced Power Supplies External N -Channel MOSFETs for High Current Capab ility Internal Boost Regulator Supply f or MOSFET Gate Drive Wide Input Range: 1.2V to 18V Fast Switching MOSFET Gate Control Input Unde.
Manufacture

Linear Technology

Datasheet
Download LT4351 Datasheet


Linear Technology LT4351

LT4351; r and Overvoltage Detection STATUS and F AULT Outputs for Monitoring Internal MO SFET Gate Clamp Available in a 10-pin M SOP The LT4351 creates a near-ideal di ode using external single or back-to-ba ck N-channel MOSFETs. This ideal diode function permits low loss ORing of mult iple power sources. Power sources can e asily be ORed together to increase tota l system power and.


Linear Technology LT4351

reliability with minimal effect on supp ly voltage or efficiency. Disparate pow er supplies can be efficiently ORed tog ether. 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 RDS(ON) is su fficiently small, the LT4351 will regul ate the voltage across the MOSFET(s) to 15mV. A STATUS pin .


Linear Technology LT4351

indicates the MOSFET on state. An intern al boost regulator generates the MOSFET gate drive voltage. Low operating volt age allows for OR’ing of supplies as low as 1.2V. The LT4351 will disable po wer passage during undervoltage or over voltage conditions. These voltages are set by resistive dividers on the UV and OV pins. The undervoltage threshold ha s user programmable .

Part

LT4351

Description

MOSFET Diode-OR Controller



Feature


( DataSheet : www.DataSheet4U.com ) LT4 351 MOSFET Diode-OR Controller FEATURE S s s DESCRIPTIO s s s s s s s Low Loss Replacement for ORing Diode in Mul tiple Sourced Power Supplies External N -Channel MOSFETs for High Current Capab ility Internal Boost Regulator Supply f or MOSFET Gate Drive Wide Input Range: 1.2V to 18V Fast Switching MOSFET Gate Control Input Unde.
Manufacture

Linear Technology

Datasheet
Download LT4351 Datasheet




 LT4351
( DataSheet : www.DataSheet4U.com )
LT4351
MOSFET Diode-OR Controller
FEATURES
s Low Loss Replacement for ORing Diode in Multiple
Sourced Power Supplies
s External N-Channel MOSFETs for High Current
Capability
s Internal Boost Regulator Supply for MOSFET
Gate Drive
s Wide Input Range: 1.2V to 18V
s Fast Switching MOSFET Gate Control
s Input Under and Overvoltage Detection
s STATUS and FAULT Outputs for Monitoring
s Internal MOSFET Gate Clamp
s Available in a 10-pin MSOP
U
APPLICATIO S
s Paralleled Power Supplies
s Uninterrupted Supplies
s High Availability Systems
s N + 1 Redundant Power Supplies
, LTC and LT are registered trademarks of Linear Technology Corporation.
DESCRIPTIO
The LT4351 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 RDS(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 OR’ing 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. Overvolt-
age detection is filtered to reduce false triggering.
The LT4351 is available in a 10-pin MSOP.
TYPICAL APPLICATIO
Dual 5V Redundant Supply
POWER
SUPPLY
1
5V
10µF
1µF
24.9k
1%
232
1%
1.47k
1%
MBR0530
4.7µH
www.DataSheet4U.com
Si4862DY
5V COMMON
Si4862DY
5V
CLOAD
VIN GATE OUT
VDD
LT4351
SW
UV STATUS
FAULT
OV GND
RLOAD
OUT
GATE
LT4351
STATUS
FAULT
GND
10µF
VIN 1µF
VDD
MBR0530
SW
4.7µH
UV
OV
POWER
SUPPLY
2
24.9k
1%
232
1%
1.47k
1%
4351 TA01
sn4351 4351fs
1




 LT4351
LT4351
ABSOLUTE AXI U RATI GS
(Note 1)
VIN Voltage ............................................... – 0.3V to 19V
OUT Voltage ............................................ – 0.3V to 19V
VDD 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
UW U
PACKAGE/ORDER I FOR ATIO
GATE 1
VDD 2
VIN 3
SW 4
GND 5
TOP VIEW
10 OUT
9 STATUS
8 FAULT
7 UV
6 OV
MS PACKAGE
10-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 120°C/W
ORDER PART
NUMBER
LT4351CMS
LT4351IMS
MS PART MARKING
LTZZ
LTA1
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT = 5V, VDD = 16.1V, VUV = 0.4V, VOV = 0.2V, GATE Open,
unless otherwise specified.
SYMBOL PARAMETER
Supply and Protection
VIN Operating Range
IVIN VIN Supply Current
VUV(TH)
IUV(HYST)
Undervoltage Turn-Off Voltage Threshold
IUV Hysteresis
IUV UV Input Bias Current
VOV(TH)
Overvoltage Threshold
IOV OV Input Bias Current
VF(ON)
FAULT Pin On Voltage
IF(OFF)
FAULT Pin Leakage Current
Boost Supply
VBR
tOFF
ISWLIM
Gate Drive
Boost Regulation Trip Voltage
Boost Supply Off Time
Boost Supply Switch Current Limit
VIOR
VGL
Input to Output Regulated Voltage
Gate Voltage Limit
VG(MAX) Maximum Gate Voltage
VGOFF
IGSO
IGSK
Gate Off Voltage
Gate Source Current
Gate Sink Current
CONDITIONS
VIN = 1.2V, VOUT = 1.1V, VDD = 12.3V
VIN = 18V, VOUT = 17.9V, VDD = 29.1V
UV Falling
Difference Between IUV at VUV(TH) + 10mV
and VUV(TH) – 10mV
VUV = VUV(TH) + 10mV
OV Rising
VOV = VOV(TH) – 10mV
IF = 5mA In Fault Condition
VF = 30V, VIN = 4.9V
Measured as VDD to VIN, Rising Edge
VIN = 5V, VOUT = 4.9V, VDD = 13V Measured with
Respect to VDD
VIN = 5V, VOUT = 4.9V, VDD = 16.1V Measured with
Respect to VOUT
VOUT = 5.1V
VOUT = 4.9V, VGATE = 9V
VOUT = 4.9V, VGATE = 9V
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
1.2
290
7
290
10.2
350
4
7
TYP MAX UNITS
18
1.41 2.0
1.71 2.1
300 310
10 13
– 100
300
– 100
0.14
0.04
– 400
310
– 400
0.25
1
V
mA
mA
mV
µA
nA
mV
nA
V
µA
10.7 11.1
600
450 650
V
ns
mA
15 25
–2.3 –3
7.4 7.8
0.16
0.670
0.670
0.30
mV
V
V
V
A
A
2
sn4351 4351fs




 LT4351
LT4351
ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT = 5V, VDD = 16.1V, VUV = 0.4V, VOV = 0.2V, GATE Open,
unless otherwise specified.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
VDD Operating Range
IVDD VDD Supply Current
Status Functions
VIN = 1.2V, VOUT = 1.1V, VDD = 12.3V, GATE Open
VIN = 18V, VOUT = 17.9V, VDD = 29.1V, GATE Open
q
q
q
30
3.0 4.0
3.6 5.6
V
mA
mA
VGIS
VIOGF
Min Gate Voltage for Turning On Status
VIN to VOUT Fault Voltage
with Open Gate
VOUT = 4.9V, ISTATUS = 1mA
VOUT Falling, Measured with Respect to VIN
q 0.75 1
185 210 230
V
mV
VSTON
ISTOFF
Status Pin On Voltage
Status Pin Leakage Current
IST = 5mA, VOUT = 4.9V, Status On
VST = 30V, Status Off, VIN = 4.9V
q
0.13 0.25
V
q
0.04 1
µA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: TJ is calculated from the ambient temperature TA and power
dissipation PD according to the following formula:
TJ = TA + (PD • 120°C/W)
TYPICAL PERFOR A CE CHARACTERISTICS
Specifications are at TA = 25°C unless otherwise specified.
Undervoltage Threshold
vs Temperature
310
VIN = 1.2V
308 VIN = 5V
306
VIN = 12V
VIN = 20V
304
302
300
298
296
294
292
290
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
4351 G01
Overvoltage Threshold
vs Temperature
305
VIN = 1.2V
VIN = 5V
303 VIN = 12V
VIN = 20V
301
299
297
295
293
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
4351 G02
Undervoltage Threshold vs VIN
310
308
306
304
302
300
298
296
294
292
290
0 2 4 6 8 10 12 14 16 18 20
VIN (V)
4351 G03
sn4351 4351fs
3






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