BQ2011_15 Datasheet, PDF (6/26 Pages) Texas Instruments – Gas Gauge IC for High Discharge Rates

bq2011
Example: Selecting a PFC Value
Given:
Sense resistor = 0.005Ω
Number of cells = 6
Capacity = 1300mAh, NiCd cells
Current range = 1A to 80A
Relative display mode
Self-discharge = ^C64
Voltage drop over sense resistor = 5mV to 400mV
Therefore:
1300mAh _* 0.005Ω = 6.5mVh
Select:
PFC = 34304 counts or 6.5mVh
PFC = Z (float)
MODE = not connected
The initial full battery capacity is 6.5mVh
(1300mAh) until the bq2011 “learns” a new capac-
ity with a qualified discharge from full to EDV.
Table 1. bq2011 Programmed Full Count mVh Selections
PFC
Programmed
Full Count (PFC)
mVh
Scale
MODE Pin
Display Mode
H
27648
10.5
1
2640
Z
34304
6.5
1
5280
Floating
Relative
L
44800
8.5
1
5280
H
42240
8.0
1
5280
Z
31744
6.0
1
5280
Connected to LEDs
Absolute
L
23808
4.5
1
5280
6