LTC4352
Low Voltage Ideal Diode
Controller with Monitoring
Features
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Description
Low Loss Replacement for Power Diode
Controls N-Channel MOSFET
0V to 18V Supply ORing or Holdup
0.5μs Turn-On and Turn-Off Time
Undervoltage and Overvoltage Protection
Open MOSFET Detect
Status and Fault Outputs
Hot Swappable
Reverse Current Enable Input
12-Pin MSOP and DFN (3mm × 3mm) Packages
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The LTC4352 regulates the forward voltage drop across
the MOSFET to ensure smooth current transfer in diodeOR applications. A fast turn-on reduces the load voltage
droop during supply switch-over. If the input supply fails
or is shorted, a fast turn-off minimizes reverse currents.
The controller operates with supplies from 2.9V to 18V.
For lower voltages, an external supply is needed at the
VCC pin. Power passage is disabled during undervoltage
or overvoltage conditions. The controller also features an
open MOSFET detect circuit that flags excessive voltage
drop across the pass transistor in the on state. A REV pin
enables reverse current, overriding the diode behavior
when desired.
Applications
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The LTC®4352 creates a near-ideal diode using an external
N-channel MOSFET. It replaces a high power Schottky diode
and the associated heat sink, saving power and board area.
The ideal diode function permits low loss power ORing
and supply holdup applications.
Redundant Power Supplies
Supply Holdup
Telecom Infrastructure
Computer Systems and Servers
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT and PowerPath are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Typical Application
2.9V to 18V Ideal Diode
Power Dissipation vs Load Current
4.0
Si7336ADP
CPO SOURCE VIN
0.1µF
VCC
UV
GATE
OUT
STATUS
LTC4352
OV
REV
FAULT
GND
4352 TA01
*OPTIONAL
3.5
TO LOAD
0.1µF*
MOSFET ON
STATUS
FAULT
POWER DISSIPATION (W)
2.9V TO 18V
3.0
DIODE (SBG1025L)
2.5
2.0
POWER
SAVED
1.5
1.0
0.5
0
MOSFET (Si7336ADP)
0
2
4
6
LOAD CURRENT (A)
8
10
4352 TA01b
4352fa
1
