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LTC1473

Dual PowerPath

TM

Switch Driver

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Power Path Management for Systems with Multiple

DC Sources

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All N-Channel Switching to Reduce Power Losses and

System Cost

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Switches and Isolates Sources Up to 30V

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Adaptive High Voltage Step-Up Regulator for N-Channel

Gate Drive

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Capacitor Inrush and Short-Circuit Current Limited

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User-Programmable Timer to Limit Switch Dissipation

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Small Footprint: 16-Pin Narrow SSOP

The LTC

single and dual battery notebook computers and other

portable equipment. The LTC1473 drives two sets of back-

to-back N-channel MOSFET switches to route power to the

input of the main system switching regulator. An internal

boost regulator provides the voltage to fully enhance the

logic level N-channel MOSFET switches.

The LTC1473 senses current to limit surge currents both

into and out of the batteries and the system supply

capacitor during switch-over transitions or during fault

conditions. A user-programmable timer monitors the time

the MOSFET switches are in current limit and latches them

off when the programmed time is exceeded.

A unique “2-diode mode” logic ensures system start-up

regardless of which input receives power first.

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Notebook Computers

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Portable Instruments

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Handi-Terminals

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Portable Medical Equipment

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Portable Industrial Control Equipment

PowerPath is a trademark of Linear Technology Corporation.

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

IN1

IN2

DIODE

TIMER

SW

GND

GA1

SAB1

GB1

GA2

SAB2

GB2

LTC1473

0.04

Ω

1

µF

1

µF

MMBD914LTI

1mH*

Si9926DY

MMBD2838LTI

1473 TA01

BAT1

DCIN

BAT2

INPUT OF SYSTEM

HIGH EFFICIENCY DC/DC

SWITCHING REGULATOR

(LTC1735, ETC)

FROM POWER

MANAGEMENT

µP

4700pF

MBRD340

Si9926DY

*COILCRAFT 1812LS-105XKBC

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16

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FEATURES

DESCRIPTIO

APPLICATIO S