DS2781 Maxim Integrated Products, DS2781 Datasheet - Page 10

• Manufacturer Part Number: DS2781
• Description: 1-Cell or 2-Cell Standalone Fuel Gauge IC
• Manufacturer: Maxim Integrated Products

ACR register update period). A write to the ACR forces the ADC to perform an offset correction conversion and
update the internal offset correction factor. Current measurement and accumulation begins with the second
conversion following a write to the ACR. Writing ACR clears the fractional values in ACRL. The Format of the ACR
register is shown in Figure 8, and the format of ACRL is shown in Figure 9.
In order to preserve the ACR value in case of power loss, the ACR value is backed up to EEPROM. The ACR
value is recovered from EEPROM on power-up. See the Memory Map in Table 2 for specific address location and
backup frequency.
Figure 8. Accumulated Current Register Format, ACR
Figure 9. Fractional/Low Accumulated Current Register Format, ACRL
ACR
ACRL
“X”: reserved
MSb
MSb
2
2
15
11
2
2
14
10
2
MSB—Address 10h
MSB—Address 12h
2
±409.6mVh
13
9
6.25 Vh
VSNS
VSNS
VSS -
VSS -
2
2
12
8
2
2
11
7
312.5 Ah
±20.48Ah
2
2
20m
20m
10
6
2
2
9
5
LSb
LSb
ACR RANGE
2
2
8
4
416.7 Ah
±27.30Ah
ACR LSb
10 of 30
15m
15m
MSb
MSb
2
2
R
R
7
3
SNS
SNS
±40.96Ah
625 Ah
2
2
10m
10m
6
2
LSB—Address 11h
2
LSB—Address 13h
2
5
1
2
2
4
0
Units:
1.250mAh
±81.92Ah
5m
5m
2
X
3
Units:1.526nVHr/R
2
X
2
6.25mVh/Rsns
Read Only
R/W & EE
2
X
1
LSb
LSb
2
X
0
SNS