DS2781
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
ACR
R/W & EE
21 20
MSB—Address 10h
215 214 213 212 211 210 29
MSb
LSB—Address 11h
25 24 23 22
28
27
26
LSb
MSb
LSb
Units:
6.25μVh/Rsns
Figure 9. Fractional/Low Accumulated Current Register Format, ACRL
ACRL
Read Only
MSB—Address 12h
LSB—Address 13h
21 20
211 210 29
28
27
26
25
24
23
22
X
X
X
X
MSb
LSb
MSb
LSb
“X”: reserved
Units:1.526nVHr/RSNS
ACR LSb
RSNS
VSS - VSNS
20mΩ
15mΩ
10mΩ
5mΩ
1.250mAh
6.25μVh
312.5μAh
416.7μAh
625μAh
ACR RANGE
RSNS
VSS - VSNS
409.6mVh
20mΩ
15mΩ
10mΩ
5mΩ
20.48Ah
27.30Ah
40.96Ah
81.92Ah
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
