BQ2011_15 Datasheet, PDF (12/26 Pages) Texas Instruments – Gas Gauge IC for High Discharge Rates

bq2011
The valid discharge flag (VDQ) is asserted when the
bq2011 is discharged from NAC=LMD. The flag remains
set until either LMD is updated or one of three actions
that can clear VDQ occurs:
n The self-discharge count register (SDCR) has
exceeded the maximum acceptable value (4096
counts) for an LMD update.
n A valid charge action equal to 256 NAC counts with
VSRO < -400µV.
n The EDV flag was set at a temperature below 0°C
The VDQ values are:
FLGS1 Bits
7
65
4
3
2
1
0
-
--
- VDQ -
-
-
Where VDQ is:
0 SDCR ≥ 4096, subsequent valid charge ac-
tion detected, or EDV is asserted with the
temperature less than 0°C
1 On first discharge after NAC = LMD
The end-of-discharge warning flag (EDV) warns the
user that the battery is empty. SEG1 blinks at a 4Hz
rate. EDV detection is disabled if VSR > VSR1. The EDV
flag is latched until a valid charge has been detected.
The EDV values are:
FLGS1 Bits
7 65 4
3
2
1
0
-
-
-
-
-
- EDV -
Where EDV is:
0 Valid charge action detected and VSB ≥
0.90V
1 VSB < 0.90V providing that VSR < VSR1
Temperature and Gas Gauge Register
(TMPGG)
The read-only TMPGG register (address=02h) contains
two data fields. The first field contains the battery tem-
perature. The second field contains the available charge
from the battery.
TMPGG Temperature Bits
7
6
5
4
3210
TMP3 TMP2 TMP1 TMP0 - - -
The bq2011 contains an internal temperature sensor.
The temperature is used to set charge and discharge ef-
ficiency factors as well as to adjust the self-discharge co-
efficient. The temperature register contents may be
translated as shown below.
TMP3 TMP2 TMP1 TMP0 Temperature
0
0
0
0
T < -30°C
0
0
0
1 -30°C < T < -20°C
0
0
1
0 -20°C < T < -10°C
0
0
1
1
-10°C < T < 0°C
0
1
0
0
0°C < T < 10°C
0
1
0
1
10°C < T < 20°C
0
1
1
0
20°C < T < 30°C
0
1
1
1
30°C < T < 40°C
1
0
0
0
40°C < T < 50°C
1
0
0
1
50°C < T < 60°C
1
0
1
0
60°C < T < 70°C
1
0
1
1
70°C < T < 80°C
1
1
0
0
T > 80°C
The bq2011 calculates the available charge as a function
of NAC, temperature, and a full reference, either LMD
or PFC. The results of the calculation are available via
the display port or the gas gauge field of the TMPGG
register. The register is used to give available capacity
in
1
16
increments
from
0
to
1516_.
TMPGG Gas Gauge Bits
7 65 4
3
2
1
0
-
--
- GG3 GG2 GG1 GG0
12