LTC2944
1
2944fa
For more information
www.linear.com/LTC2944
Typical applicaTion
FeaTures
DescripTion
60V Battery Gas Gauge
with Temperature, Voltage
and Current Measurement
The
LTC
®
2944
measures battery charge state, battery volt-
age, battery current and its own temperature in portable
product applications. The wide input voltage range allows
use with multicell batteries up to 60V. A precision coulomb
counter integrates current through a sense resistor between
the battery’s positive terminal and the load or charger.
Voltage, current and temperature are measured with an
internal 14-bit No Latency Δ
Σ
™ ADC. The measurements
are stored in internal registers accessible via the onboard
I
2
C/SMBus Interface.
The LTC2944 features programmable high and low thresh-
olds for all four 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 LTC2944 requires only
a single low value sense resistor to set the measured
current range.
Total Charge Error vs
Differential Sense Voltage
applicaTions
n
Measures Accumulated Battery Charge
and Discharge
n
3.6V to 60V Operating Range for Multiple Cells
n
14-Bit ADC Measures Voltage, Current
and Temperature
n
1% Voltage, Current and Charge Accuracy
n
±50mV Sense Voltage Range
n
High Side Sense
n
I
2
C Interface/SMBus Interface
n
General Purpose Measurements for Any Battery
Chemistry and Capacity
n
Configurable Alert Output/Charge Complete Input
n
Quiescent Current Less Than 150µA
n
Small 8-Lead 3mm × 3mm DFN Package
n
Electric and Hybrid Electric Vehicles
n
Power Tools
n
Electric Bicycles, Motorcycles, Scooters
n
High Power Portable Equipment
n
Photo Voltaics
n
Backup Battery Systems
All registered trademarks and trademarks are the property of their respective owners.
SENSE
+
ALCC
SDA
SCL
LTC2944
CHARGER
2k
2k
2k
1A
LOAD
R
SENSE
50mΩ
MULTICELL
Li-ION
2944 TA01a
SENSE
–
+
GND
1µF
V
DD
3.3V
µP
V
SENSE
(mV)
0.1
–1
CHARGE ERROR (%)
0
–2
2
1
1
10
100
2944 TA01b
–3
3
V
SENSE
+
= 3.6V TO 60V
