LTC1760_11 Datasheet, PDF (1/48 Pages) Linear Technology – Dual Smart Battery System Manager Available in 48-Lead TSSOP Package

FEATURES
n _{SMBus Charger/Selector for Two Smart Batteries*}
n _{Voltage and Current Accuracy within 0.2% of Value}
Reported by Battery
n _{Simplifies Construction of “Smart Battery System}
Manager”
n _{Includes All SMBus Charger V1.1 Safety Features}
n _{Supports Autonomous Operation without a Host}
n _{Allows Both Batteries to Discharge Simultaneously}
into Single Load with Low Loss (Ideal Diode)
n _{SMBus Switching for Dual Batteries with Alarm}
Monitoring for Charging Battery at All Times
n _{Pin Programmable Limits for Maximum Charge}
Current and Voltage Improve Safety
n _{Fast Autonomous PowerPath™ Switching (<10μs)}
n _{Low Loss Simultaneous Charging of Two Batteries}
n _{>95% Efficient Synchronous Buck Charger}
n _{AC Adapter Current Limiting* Maximizes Charge Rate}
n _{SMBus Accelerator Improves SMBus Timing**}
n _{Available in 48-Lead TSSOP Package}
APPLICATIONS
n _{Portable Computers and Instruments}
n _{Standalone Dual Smart Battery Chargers}
n _{Battery Backup Systems}
LTC1760
Dual Smart Battery
System Manager
DESCRIPTION
The LTC^®1760 Smart Battery System Manager is a highly-
integrated SMBus Level 3 battery charger and selector
intended for products using dual smart batteries. Three
SMBus interfaces allow the LTC1760 to servo to the
internal voltage and currents measured by the batteries
while allowing an SMBus Host device to monitor either
battery’s status. Charging accuracy is determined by the
battery’s internal voltage and current measurements, typi-
cally better than ±0.2%.
A proprietary PowerPath architecture supports simultane-
ous charging or discharging of both batteries. Typical battery
run times are extended by up to 10%, while charging times
are reduced by up to 50%. The LTC1760 automatically
switches between power sources in less than 10μs to prevent
power interruption upon battery or wall adapter removal.
The LTC1760 implements all elements of a version 1.1
“Smart Battery System Manager” except for the generation
of composite battery information. An internal multiplexer
cleanly switches the SMBus Host to either of the two
attached Smart Batteries without generating partial mes-
sages to batteries or SMBus Host. Thermistors on both
batteries are automatically monitored for temperature and
disconnection information (SafetySignal).
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents including *5723970 **6650174.
TYPICAL APPLICATION
Dual Battery Charger/Selector System Architecture
DC
IN
SYSTEM
POWER
LTC1760
SMBus (HOST)
SafetySignal 1
SMBus 1
SafetySignal 2
SMBus 2
1760 TA01
Dual vs Sequential Charging
3500
3000
2500
BAT1
CURRENT
BAT2
CURRENT
2000
SEQUENTIAL
1500
1000
500
0
3500
3000
2500
2000
BAT1
CURRENT
BAT2
CURRENT
DUAL
1500
1000
500
0
0
100
MINUTES
50 100 150 200 250 300
TIME (MINUTES)
BATTERY TYPE: 10.8V Li-Ion (MOLTECH NI2020)
REQUESTED CURRENT = 3A
REQUESTED VOLTAGE = 12.3V
MAX CHARGER CURRENT = 4.1A
1760 TA03
1760fa
1