LTC4355
Positive High Voltage
Ideal Diode-OR with Input Supply
and Fuse Monitors
Features Description
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Replaces Power Schottky Diodes The LTC 4355 is a positive voltage ideal diode-OR control-
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Controls N-Channel MOSFETs ler that drives two external N-channel MOSFETs. Forming
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0.3s Turn-Off Time Limits Peak Fault Current the diode-OR with N-channel MOSFETs instead of Schottky
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Wide Operating Voltage Range: 9V to 80V diodes reduces power consumption, heat dissipation and
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Smooth Switchover without Oscillation PC board area.
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No Reverse DC Current
With the LTC4355, power sources can easily be ORed
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Monitors V , Fuse, and MOSFET Diode
IN
together to increase total system reliability. The LTC4355
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Available in 14-Lead (4mm 3mm) DFN,
can diode-OR two positive supplies or the return paths of
16-Lead MS and SO Packages
two negative supplies, such as in a 48V system.
In the forward direction the LTC4355 controls the volt-
a
age drop across the MOSFET to ensure smooth current
transfer from one path to the other without oscillation. If
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High Availability Systems
a power source fails or is shorted, fast turnoff minimizes
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AdvancedTCA (ATCA) Systems
reverse current transients.
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+48V and 48V Distributed Power Systems
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Telecom Infrastructure
Power fault detection indicates if the input supplies are
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and not in regulation, the inline fuses are blown, or the volt-
Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the
ages across the MOSFETs are greater than the fault
property of their respective owners.
threshold.
t ypical a
+48V Diode-OR Power Dissipation vs Load Current
7A 6
FDB3632
TO
V = +48V
IN1
LOAD
5
7A
FDB3632
DIODE (MBR10100)
V = +48V
IN2
22k 22k 22k
4
340k 340k 22k 22k
3 POWER
IN1 GATE1 IN2 GATE2 OUT
SAVED
MON1 VDSFLT
2
FUSEFLT1
LTC4355
SET
FUSEFLT2
PWRFLT1
1
MON2 GND PWRFLT2
FET (FDB3632)
0
12.7k 12.7k
GREEN LEDs
0 2 4 6 8 10
PANASONIC LN1351C
CURRENT (A)
GND 4355 TA02
4355 TA01
4355ff
1
For more information www.linear.com/LTC4355
POWER DISSIPATION (W)
pplication
pplicationsLTC4355
a bsolute Maxi Mu M r
(Notes 1, 2)
Supply Voltages Operating Ambient Temperature Range
IN1, IN2 .................................................. 1V to 100V LTC4355C ................................................ 0C to 70C
OUT ..................................................... 0.3V to 100V LTC4355I..............................................40C to 85C
Input Voltages LTC4355H ..........................................40C to 125C
MON1, MON2, SET .................................. 0.3V to 7V Storage Temperature Range ...................65C to 150C
Output Voltages Lead Temperature (Soldering, 10 sec)
GATE1 (Note 3) ................... V 0.2V to V + 13V MS, SO Packages ............................................. 300C
IN1 IN1
GATE2 (Note 3) ................... V 0.2V to V + 13V
IN2 IN2
PWRFLT1, PWRFLT2, VDSFLT,
FUSEFLT1, FUSEFLT2 ............................... 0.3V to 8V
pin con F
TOP VIEW
TOP VIEW
IN1 1 16 MON1
IN1 1 14 MON1 TOP VIEW
GATE1 2 15 PWRFLT1
GATE1 2 13 PWRFLT1 1
IN1 16 MON1
NC 3 14 FUSEFLT1
GATE1 2 15 PWRFLT1
OUT 3 12 FUSEFLT1
3
NC 14 FUSEFLT1
15
OUT 4 13 FUSEFLT2
GATE2 4 11 FUSEFLT2 OUT 4 13 FUSEFLT2
5
NC 12 PWRFLT2
NC 5 12 PWRFLT2
IN2 5 10 PWRFLT2
GATE2 6 11 MON2
VDSFLT 6 9 MON2 7
IN2 10 SET GATE2 6 11 MON2
VDSFLT 8 9 GND
GND 7 8 SET
IN2 7 10 SET
MS PACKAGE
NC 8 9 GND
16-LEAD PLASTIC MSOP
DE14 PACKAGE
T = 125C, = 120C/W
14-LEAD (4mm 3mm) PLASTIC DFN
JMAX JA
S PACKAGE
T = 125C, = 43C/W
JMAX JA
16-LEAD PLASTIC SO
EXPOSED PAD (PIN 15) PCB GND CONNECTION OPTIONAL
T = 125C, = 80C/W
JMAX JA
Der in F M
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC4355CDE#PBF LTC4355CDE#TRPBF 4355 14-Lead (4mm 3mm) Plastic DFN 0C to 70C
LTC4355IDE#PBF LTC4355IDE#TRPBF 4355 40C to 85C
14-Lead (4mm 3mm) Plastic DFN
LTC4355CS#PBF LTC4355CS#TRPBF LTC4355CS 16-Lead Plastic SO 0C to 70C
LTC4355IS#PBF LTC4355IS#TRPBF LTC4355IS 16-Lead Plastic SO 40C to 85C
LTC4355CMS#PBF LTC4355CMS#TRPBF 4355 16-Lead Plastic MSOP 0C to 70C
LTC4355IMS#PBF LTC4355IMS#TRPBF 4355 16-Lead Plastic MSOP 40C to 85C
LTC4355HMS#PBF LTC4355HMS#TRPBF 4355 16-Lead Plastic MSOP 40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: