Figure 6. accumulation bias register format, Voltage measurement, Figure 7. voltage register format – Rainbow Electronics DS2756 User Manual
Page 9: Temperature measurement, Figure 8. temperature register format
DS2756: High-Accuracy Battery Fuel Gauge with Programmable Suspend Mode
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Figure 6. Accumulation Bias Register Format
Address
33h
S 2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb
LSb
“S”:
sign
bit
1.95
mV/Rsns
VOLTAGE MEASUREMENT
The voltage register operates in two modes, normal and snapshot. In normal mode, the DS2756 continually
measures the voltage between pins V
IN
and V
SS
over a 0 to 4.75V range, and the Voltage Register is updated in
two’s-complement format every 3.4ms with a resolution of 4.88mV.
In snapshot mode, the Voltage register holds the voltage measured immediately following the snapshot trigger.
Normal voltage measurements resume after the snapshot value is obtained, however, the SNAP bit must be
cleared to re-enable normal mode reporting of voltage measurement to the Voltage register.
Voltages above the maximum register value are reported as the maximum value.
Figure 7. Voltage Register Format
MSB-Address
0Ch LSB-Address
0Dh
S 2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
X X X X X
MSb
LSb
MSb
LSb
Units: 4.88 mV
TEMPERATURE MEASUREMENT
The DS2756 uses an integrated temperature sensor to continually measure battery temperature. Temperature
measurements are updated in the Temperature Register every 220ms in two’s-complement format with a resolution
of 0.125°C over a
±127°C range. The Temperature Register format is shown in Figure 8.
Figure 8. Temperature Register Format
MSB-Address
18h LSB-Address
19h
S 2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
X X X X X
MSb
LSb
MSb
LSb
Units: 0.125
°C