LTC1960_11 Datasheet, PDF (1/28 Pages) Linear Technology – Dual Battery Charger/ Selector with SPI Interface

FEATURES
n _{Complete Dual-Battery Charger/Selector System}
n _{Serial SPI Interface Allows External µC Control and}
Monitoring
n _{Simultaneous Dual-Battery Discharge Extends Run}
Time by Typically 10%
n _{Simultaneous Dual-Battery Charging Reduces}
Charging Time by Up to 50%
n _{Automatic PowerPath™ Switching in <10µs}
Prevents Power Interruption
n _{Circuit Breaker Protects Against Overcurrent Faults}
n _{5% Accurate Adapter Current Limit Maximizes}
Charging Rate
n _{95% Efficient Synchronous Buck Charger}
n _{Charger Has Low 0.5V Dropout Voltage}
n _{No Audible Noise Generation, Even with Ceramic}
Capacitors
n _{11-Bit VDAC Delivers 0.8% Voltage Accuracy}
n _{10-Bit IDAC Delivers 5% Current Accuracy}
n _{VIN Up to 32V; VBATT Up to 28V}
n _{Available in 5mm × 7mm 38-Pin QFN and 36-Pin}
Narrow SSOP Packages
APPLICATIONS
n _{Portable Computers}
n _{Portable Instruments}
LTC1960
Dual Battery Charger/
Selector with SPI Interface
DESCRIPTION
The LTC^®1960 is a highly integrated battery charger and
selector intended for portable products using dual smart
batteries. A serial SPI interface allows an external microcon-
troller to control and monitor status of both batteries.
A proprietary PowerPath architecture supports simulta-
neous charging or discharging of both batteries. Typical
battery run times are extended by 10%, while charging
times are reduced by up to 50%. The LTC1960 automati-
cally switches between power sources in less than 10µs
to prevent power interruption upon battery or wall adapter
removal.
The synchronous buck battery charger delivers 95% effi-
ciency with only 0.5V dropout voltage, and prevents audible
noise in all operating modes. Patented input current limit-
ing with 5% accuracy charges batteries in the shortest
possible time without overloading the wall adapter.
The LTC1960’s 5mm × 7mm 38-pin QFN and 36-pin nar-
row SSOP packages allow implementation of a complete
SBS-compliant dual battery system while consuming
minimum PCB area.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
No R_SENSE and PowerPath are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Protected by U.S. Patents, including
5481178, 5723970, 6304066, 6580258.
TYPICAL APPLICATION
LTC1960 Dual Battery/Selector System Architecture
DC
IN
SYSTEM POWER
BAT2 BAT1
LTC1960
MICROCONTROLLER
4
SPI
SMBus
1960 TA01
Dual vs Sequential Charging
3500
3000
2500
BAT1
CURRENT
BAT2
CURRENT
2000
1500
SEQUENTIAL
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
1960 TA01b
1960fb
1