LTC1479 Datasheet, PDF (1/24 Pages) Linear Technology – PowerPath Controller for Dual Battery Systems

LTC1479
PowerPath Controller
for Dual Battery Systems
FEATURES
s _{Complete Power Path Management for Two}
Batteries, DC Power Source, Charger and Backup
s _{Compatible with Li-Ion, NiCd, NiMH and Lead-Acid}
Battery Chemistries
s _{“3-Diode” Mode Ensures Powers is Available}
under “Cold Start” Conditions
s _{All N-Channel Switching Reduces Power Losses}
s _{Capacitor and Battery Inrush Current Limited}
s _{“Seamless” Switching Between Power Sources}
s _{Independent Charging and Monitoring of Two}
Battery Packs
s _{New, Small FootpUrint, 36-Lead SSOP Package}
APPLICATIONS
s _{Notebook Computer Power Management}
s _{Portable Instruments}
s _{Handheld Terminals}
s _{Portable Medical Equipment}
s _{Portable Industrial Control Equipment}
DESCRIPTION
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.
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 di-
rectly to the LT1510, LT1511 and LT1620/LTC1435 bat-
tery charging circuits.
, LTC and LT are registered trademarks of Linear Technology Corporation.
PowerPath is a trademark of Linear Technology Corporation.
TYPICAL APPLICATION
Dual Battery PowerPath^TM Controller System Block Diagram
AC
ADAPTER
DCIN
BAT1
SW A/B
SW C/D
R_SENSE
HIGH EFFICIENCY
DC/DC SWITCHING
SW E/F
+
REGULATOR
(LTC1435/LTC1438
5V
CIN
ETC.)
SW G
SW H
BAT2
BATTERY CHARGER
(LT1510/LT1511/
LT1620/LTC1435)
BACKUP
REGULATOR
(LT1304)
LTC1479
PowerPath CONTROLLER
STATUS &
CONTROL
POWER
MANAGEMENT
µP
1479 TA01
1