LTC1479
PowerPath Controller
for Dual Battery Systems
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DESCRIPTION
FEATURES
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The LTC ®1479 is the “heart” of a total power management
solution for single and dual battery notebook computers
and other portable equipment. The LTC1479 directs power
from up to two battery packs and a DC power source to the
input of the main system switching regulator. It works in
concert with related LTC power management products
(e.g. LTC1435, LT ®1511, etc.) to create a total system
solution; starting from the batteries and the DC power
source, and ending at the input of each of the computer’s
complex loads. A system-provided power management
µP monitors and actively directs the LTC1479.
Complete Power Path Management for Two
Batteries, DC Power Source, Charger and Backup
Compatible with Li-Ion, NiCd, NiMH and Lead-Acid
Battery Chemistries
“3-Diode” Mode Ensures Powers is Available
under “Cold Start” Conditions
All N-Channel Switching Reduces Power Losses
Capacitor and Battery Inrush Current Limited
“Seamless” Switching Between Power Sources
Independent Charging and Monitoring of Two
Battery Packs
New, Small Footprint, 36-Lead SSOP Package
The LTC1479 uses low loss N-channel MOSFET switches
to direct power from three main sources. An adaptive
current limiting scheme reduces capacitor and battery
inrush current by controlling the gates of the MOSFET
switches during transitions. The LTC1479 interfaces directly to the LT1510, LT1511 and LT1620/LTC1435 battery charging circuits.
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APPLICATIONS
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Notebook Computer Power Management
Portable Instruments
Handheld Terminals
Portable Medical Equipment
Portable Industrial Control Equipment
, LTC and LT are registered trademarks of Linear Technology Corporation.
PowerPath is a trademark of Linear Technology Corporation.
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TYPICAL APPLICATION
Dual Battery PowerPathTM Controller System Block Diagram
AC
ADAPTER
SW A/B
DCIN
SW C/D
RSENSE
+
SW E/F
BAT1
SW G
CIN
HIGH EFFICIENCY
DC/DC SWITCHING
REGULATOR
(LTC1435/LTC1438
ETC.)
5V
SW H
BAT2
BATTERY CHARGER
(LT1510/LT1511/
LT1620/LTC1435)
BACKUP
REGULATOR
(LT1304)
LTC1479
PowerPath CONTROLLER
STATUS &
CONTROL
POWER
MANAGEMENT
µP
1479 TA01
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