Datasheet
DS2780 Standalone Fuel Gauge IC
11 of 31
ACR RANGE
R
SNS
VSS
-
VSNS
20m 15m 10m 5m
±409.6mVh ±20.48Ah ±27.30Ah ±40.96Ah ±81.92Ah
ACCUMULATION BIAS
The Accumulation Bias register (AB) allows an arbitrary bias to be introduced into the current-accumulation
process. The AB can be used to account for currents that do not flow through the sense resistor, estimate currents
too small to measure, estimate battery self-discharge or correct for static offset of the DS2780. The AB register
allows a user programmed constant positive or negative polarity bias to be included in the current accumulation
process. The user-programmed two’s compliment value, with bit weighting the same as the current register, is
added to the ACR once per current conversion cycle. The AB value is loaded on power-up from EEPROM. The
format of the AB register is shown in Figure 10.
Figure 10. Accumulation Bias Register Formats
AB
EE
Address 61h
S 2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb LSb
“S”: sign bit Units: 1.5625V/Rsns
CAPACITY ESTIMATION ALGORITHM
Remaining capacity estimation uses real-time measured values, stored parameters describing the cell
characteristics, and application operating limits. The following diagram describes the algorithm inputs and outputs.