LTC2942-1_15 Datasheet, PDF (1/16 Pages) Linear Technology – 1A Battery Gas Gauge with Internal Sense Resistor and Temperature/Voltage Measurement

Features
n _{Indicates Accumulated Battery Charge and}
Discharge
n _SMBus/I²_{C Interface}
n _{Integrated 50mΩ High Side Sense Resistor}
n _{±1A Sense Current Range}
n _{High Accuracy Analog Integration}
n _{ADC Measures Battery Voltage and Temperature}
n _{Integrated Temperature Sensor}
n _{1% Voltage and Charge Accuracy}
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
LTC2942-1
1A Battery Gas Gauge with
Internal Sense Resistor and
Temperature/Voltage
Measurement
Description
The LTC^®2942-1 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
counter integrates current through an internal 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 ∆Σ™
ADC. The three measured quantities (charge, voltage and
temperature) are stored in internal registers accessible via
the onboard SMBus/I²C interface.
The LTC2942-1 features programmable high and low
thresholds for all three measured quantities. If a pro-
grammed threshold is exceeded, the device communicates
an alert using either the SMBus alert protocol or by setting
a flag in the internal status register.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
No Latency ∆Σ, 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⁺
LTC2942-1
AL/CC
SDA
SENSE^–
SCL
GND
LOAD
0.1µF
+ _1-CELL
Li-Ion
29421 TA01a
Total Charge Error vs Sense Current
1.00
V_SENSE+ = 3.6V
0.75
0.50
0.25
0
–0.25
–0.50
–0.75
–1.00
1
10
100
|I_SENSE| (mA)
1000
29421 TA01b
29421f