ds2762ax-t-r Maxim Integrated Products, Inc., ds2762ax-t-r Datasheet - Page 12

• Manufacturer Part Number: ds2762ax-t-r
• Description: Ds2762 High-precision Li+ Battery Monitor With Alerts
• Manufacturer: Maxim Integrated Products, Inc.

CURRENT OFFSET COMPENSATION
Current measurement and current accumulation are internally compensated for offset on a continual basis
minimizing error resulting from variations in device temperature and voltage. Additionally, a constant bias can be
used to alter any other sources of offset. This bias resides in EEPROM address 33h in two’s-complement format
and is subtracted from each current measurement. The current offset bias is applied to the internal and external
sense resistor configurations. The factory default for the current offset bias is 0.
Figure 6. Current Offset Bias
VOLTAGE MEASUREMENT
The DS2762 continually measures the voltage between pins V
register is updated in two’s-complement format every 3.4ms with a 4.88mV resolution. Voltages above the
maximum register value are reported as the maximum value. Figure 7 shows the voltage register format.
Figure 7. Voltage Register Format
TEMPERATURE MEASUREMENT
The DS2762 uses an integrated temperature sensor to continually measure battery temperature. Temperature
measurements are placed in the temperature register every 220ms in two’s-complement format with a 0.125°C
resolution over a ±127°C range. Figure 8 shows the temperature register format.
Figure 8. Temperature Register Format
MSb
MSb
S
S
2
2
9
9
2
2
MSB—Address 0C
MSB—Address 18
8
8
2
2
7
7
2
2
6
6
MSb
S
2
2
5
5
2
6
2
2
4
4
2
Units: 0.625mA for Internal Sense Resistor
5
LSb
LSb
2
2
Address 33
3
3
15.625mV for External Sense Resistor
12 of 25
2
4
2
3
MSb
MSb
2
2
2
2
IN
2
2
and V
2
2
1
1
2
1
SS
2
2
LSB—Address 0D
LSB—Address 19
LSb
0
0
over a 0 to 4.75V range. The voltage
2
0
X
X
X
X
X
X
Units: 0.125°C
Units: 4.88mV
X
X
LSb
LSb
X
X