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LTC4414

4414fc

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other

trademarks are the property of their respective owners.

FORWARD VOLTAGE (V)

0.02

0

8.0

3.6

CONSTANT

4414 TA01b

0.5

CONSTANT

VOLTAGE

SCHOTTKY

DIODE

LTC4414

GND

CTL

NC

SENSE

GATE

STAT

NC

LTC4414

TO LOAD

STATUS OUTPUT

LOW WHEN POWER

SUPPLY PRESENT

470k

UPS840

SUP75P03_07

BATTERY

CELL(S)

POWER

SUPPLY

INPUT

Automatic Switchover of Load Between a Battery and a Power Supply

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

36V, Low Loss PowerPath

TM

Controller for Large PFETs

OR’ing Diodes

µA

The LTC

create a near ideal diode function for power switchover.

This permits highly efficient OR’ing of multiple power

sources for extended battery life and low self- heating. When

conducting, the voltage drop across the MOSFET is typi-

cally 20mV. For applications with a wall adapter or other aux-

iliary power source, the load is automatically disconnected

from the battery when the auxiliary source is connected.

Two or more LTC4414s may be interconnected to allow

switchover between multiple batteries or charging of mul-

tiple batteries from a single charger.

The wide supply operating range supports operation from

one to eight Li-Ion cells in series. The low quiescent

current (30

µA typical) is independent of the load current.

The gate driver includes an internal voltage clamp for

MOSFET protection.

The STAT pin can be used to enable an auxiliary P-channel

MOSFET power switch when an auxiliary supply is

detected. This pin may also be used to indicate to a micro-

controller that an auxiliary supply is connected. The con-

trol (CTL) input enables the user to force the primary

MOSFET off and the STAT pin low.

The LTC4414 is available in a low profile 8-lead MSOP

package.

LTC4414 vs Schottky Diode Forward Voltage Drop