LTC2941_15 Datasheet, PDF (1/16 Pages) Linear Technology – Battery Gas Gauge with IC Interface

Features
n _{Indicates Accumulated Battery Charge and}
Discharge
n _{High Accuracy Analog Integration}
n _{High Side Sense}
n _{1% Charge Accuracy}
n _{±50mV Sense Voltage Range}
n _SMBus/I²_{C Interface}
n _{Configurable Alert Output/Charge Complete Input}
n _{2.7V to 5.5V Operating Range}
n _{Quiescent Current Less Than 100µA}
n _{Small 6-Pin 2mm × 3mm DFN Package}
Applications
n _{Low Power Handheld Products}
n _{Cellular Phones}
n _{MP3 Player}
n _Cameras
n _GPS
LTC2941
Battery Gas Gauge
with I²C Interface
Description
The LTC^®2941 measures battery charge state in battery-
supplied handheld PC and portable product applications.
Its operating range is perfectly suited for single-cell Li-Ion
batteries. A precision coulomb counter integrates current
through a sense resistor between the battery’s positive
terminal and the load or charger. The measured charge
is stored in internal registers. An SMBus/I²C interface
accesses and configures the device.
The LTC2941 features programmable high and low thresh-
olds for accumulated charge. If a threshold is exceeded, the
device communicates an alert using either the SMBus alert
protocol or by setting a flag in the internal status register.
The LTC2941 requires only a single low value external
sense resistor to set the current range.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT and Bat-Track are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Typical Application
CHARGER
I²C/SMBus
TO HOST
SENSE⁺
LTC2941
AL/CC
SDA SENSE^–
SCL
GND
R_SENSE
100mΩ
+ _1-CELL
Li-Ion
2941 TA01a
LOAD
0.1µF
Total Charge Error vs
Differential Sense Voltage
2.0
V_SENSE+ = 3.6V
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0.1
1
10
V_SENSE (mV)
100
2941 TA01b
2941fa
1