LTC2942 Datasheet, PDF (1/16 Pages) Linear Technology – Battery Gas Gauge with Temperature, Voltage Measurement

LTC2942
Battery Gas Gauge
with Temperature,
Voltage Measurement
FEATURES
n _{Indicates Accumulated Battery Charge and}
Discharge
n _{High Accuracy Analog Integration}
n _{ADC Measures Battery Voltage and Temperature}
n _{Integrated Temperature Sensor}
n _{High Side Sense}
n _{1% Voltage and 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 Players}
n _Cameras
n _GPS
TYPICAL APPLICATION
CHARGER
I²C/SMBus
TO HOST
SENSE⁺
LTC2942
AL/CC
SDA SENSE^–
SCL
GND
R_SENSE
100mΩ
+ _1-CELL
Li-Ion
2942 TA01a
LOAD
0.1μF
DESCRIPTION
The LTC^®2942 measures battery charge state, battery
voltage and chip temperature in handheld PC and portable
product applications. Its operating range is perfectly suited
for single cell Li-Ion batteries. A precision coulomb coun-
ter integrates current through a sense resistor between
the battery’s positive terminal and the load or charger.
Battery voltage and on-chip temperature are measured
with an internal 14-bit No Latency ΔΣ™ ADC. The three
measured quantities (charge, voltage and temperature)
are stored in internal registers accessible via the onboard
SMBus/I²C interface.
The LTC2942 features programmable high and low thresh-
olds for all three measured quantities. If a programmed
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 LTC2942 requires only a single low value sense resis-
tor to set the measured current range.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. No Latency ΔΣ is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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
2942 TA01b
2942f
1