Fullcapnom register (23h), Qh register (4dh), Application-specific registers – Rainbow Electronics MAX17047 User Manual
Page 19: Designcap register (18h), Figure 21. fullcapnom register format (o, Figure 22. qh register format (output), Figure 23. designcap register format (in
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MAX17047
ModelGauge m3 Fuel Gauge
Figure 21. FullCapNom Register Format (Output)
FullCapNom Register (23h)
This register holds the calculated full capacity of the cell,
not including temperature and charger tolerance. New
full capacity values are calculated periodically by the IC
during operation. The value is stored in terms of FVh and
must be divided by the application sense resistor value
to determine capacity in mAh. This register is used to
calculate the outputs of the ModelGauge m3 algorithm
and is available to the user only for debug.
is
the FullCapNom register format.
QH Register (4Dh)
The QH register displays the raw coulomb count gener-
ated by the device. This register is used internally as an
input to the mixing algorithm. Monitoring changes in QH
over time can be useful for debugging device operation.
The QH register is set to 0000h at power-up. The QH reg-
ister format is shown in
Application-Specific Registers
The following registers define the behavior of the applica-
tion. They must be programmed by the user before the
ModelGauge m3 algorithm is accurate. Any changes to
these register values require recharacterization of the cell.
DesignCap Register (18h)
The DesignCap register holds the expected capacity of
the cell. This value is used to determine age and health
of the cell by comparing against the calculated pres-
ent capacity stored in the FullCAP register. DesignCap
has an LSb equal to 5.0FVh and a full range of 0 to
327.68mVh. The user should multiply the mAh capac-
ity of the cell by the sense resistor value to determine
the FVh value to store in the DesignCap register. The
DesignCap register format is shown in
Figure 22. QH Register Format (Output)
Figure 23. DesignCap Register Format (Input)
MSB—ADDRESS 23h
LSB—ADDRESS 23h
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb
LSb
MSb
LSb
2
0
UNITS: 5.0FVh/R
SENSE
(0.5mAh WHEN R
SENSE
= 0.010I)
MSB—Address 4Dh
LSB—ADDRESS 4Dh
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb
LSb
MSb
LSb
2
0
UNITS: 5.0FVh/R
SENSE
(0.5mAh WHEN R
SENSE
= 0.010I)
MSB—ADDRESS 18h
LSB—ADDRESS 18h
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
MSb
LSb
MSb
LSb
2
0
UNITS: 5.0FVh/R
SENSE
(0.5mAh WHEN R
SENSE
= 0.010I)