MAX17047/MAX17050
ModelGauge m3 Fuel Gauge
value is an unfiltered calculation. Jumps in the value can
be caused by changes in the application such as abrupt
SOC
Register (0Eh)
AV
The SOC
register holds the calculated present state
AV
changes in load current. Figure 15 shows the RemCap
register format.
of charge of the cell based on all inputs from the
ModelGauge m3 algorithm including empty compensa-
tion. The register value is stored as a percentage with a
resolution of 0.0039% per LSb. If an 8-bit state-of-charge
value is desired, the host can discard the lower byte and
use only the upper byte of the register with a resolution of
1.0%. The SOC register value is an unfiltered calcula-
tion. Jumps in the value can be caused by changes in
the application such as abrupt changes in load current.
AV
SOC
Register (FFh)
VF
The SOC register holds the calculated present SOC of
VF
the battery according to the voltage fuel gauge. The reg-
ister value is stored as a percentage with a resolution of
0.0039% per LSb. If an 8-bit SOC value is desired, the host
can discard the lower byte and use only the upper byte of
the register with a resolution of 1.0%. Figure 16 shows the
AV
Figure 14 shows the SOC register format.
AV
SOC register format.
VF
RemCap
Register (1Fh)
AV
TTE Register (11h)
The TTE register holds the estimated time to empty for
the application under present conditions. The TTE value
The RemCap
register holds the calculated remain-
AV
ing capacity of the cell based on all inputs from the
ModelGauge m3 algorithm including empty compen-
sation. The value is stored in terms of FVh and must
be divided by the application sense-resistor value to
determine the remaining capacity in mAh. The register
is determined by dividing the RemCap register by the
AV
AverageCurrent register. The result is stored in the TTE
register with a resolution of 5.625s per LSb.
MSB—ADDRESS 0Eh
LSB—ADDRESS 0Eh
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
-8
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
MSb
LSb
MSb
-8
LSb
2
UNITS: 0.0039%
2 UNITS: 1.0%
0
Figure 14. SOC Register Format (Output)
AV
MSB—ADDRESS 1Fh
LSB—ADDRESS 1Fh
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
MSb
LSb
MSb
0
LSb
2 UNITS: 5.0FVh/R
SENSE
(0.5mAh WHEN R
= 0.010I)
SENSE
Figure 15. RemCap Register Format (Output)
AV
MSB—ADDRESS FFh
LSB—ADDRESS FFh
7
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
-8
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
MSb
LSb
MSb
-8
LSb
2
UNITS: 0.0039%
0
2 UNITS: 1.0%
Figure 16. SOC Register Format (Output)
VF
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