Rainbow Electronics MAX17047 - Manual (Page 33)

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MAX17047
ModelGauge m3 Fuel Gauge
Note that if this bit is set to 1, the Bei, Ber, and Aen bits
should be set to 0 to prevent an alert condition from caus-
ing the device to enter shutdown mode.
I2CSH—I
2 C Shutdown. Set to logic 1 to force the device
to enter shutdown mode if both SDA and SCL are held
low for more than timeout of the SHDNTIMER register.
This also configures the device to wake up on a rising
edge of either SDA or SCL. Set to 1 at power-up. Note
that if I2SCH and AINSH are both set to 0, the device
wakes up an edge of any of the SDA, SCL, or ALRT pins.
SHDN—Shutdown. Write this bit to logic 1 to force a
shutdown of the device after timeout of the SHDNTIMER
register. SHDN is reset to 0 at power-up and upon exiting
shutdown mode.
Tex—Temperature External. When set to 1, the fuel gauge
requires external temperature measurements to be written
from the host. When set to 0, measurements on the AIN
pin are converted to a temperature value and stored in the
Temperature register instead. Tex is set to 1 at power-up.
Ten—Enable Temperature Channel. Set to 1 and set
ETHRM or FTHRM to 1 to enable measurements on the
AIN pin. Ten is set to 1 at power-up.
AINSH—AIN Pin Shutdown. Set to 1 to enable device shut-
down when the battery is removed. The IC enters shutdown
if the AIN pin remains high (AIN reading > V
THRM
- V
DETR
)
for longer than the timeout of the SHDNTIMER register. This
also configures the device to wake up when AIN is pulled low
on cell insertion. AINSH is set to 0 at power-up. Note that if
I2SCH and AINSH are both set to 0, the device wakes up an
edge of any of the SDA, SCL, or ALRT pins.
ALRTp—ALRT Pin Polarity. Regardless if ALRT is being
used as an input or output, if ALRTp = 0, the ALRT pin
is active low; if ALRTp = 1, the ALRT pin is active high.
ALRTp is set to 0 at power-up.
V
S
—Voltage ALRT Sticky. When V
S
= 1, voltage alerts
can only be cleared through software. When V
S
= 0, volt-
age alerts are cleared automatically when the threshold
is no longer exceeded. V
S
is set to 0 at power-up.
T
S
—Temperature ALRT Sticky. When T
S
= 1, tempera-
ture alerts can only be cleared through software. When
T
S
= 0, temperature alerts are cleared automatically
when the threshold is no longer exceeded. T
S
is set to 1
at power-up.
S
S
—SOC ALRT Sticky. When S
S
= 1, SOC alerts can
only be cleared through software. When S
S
= 0, SOC
alerts are cleared automatically when the threshold is no
longer exceeded. S
S
is set to 0 at power-up.
TIMER Register (3Eh)
This register holds timing information for the fuel gauge.
It is available to the user for debug purposes.
Figure 44
shows the TIMER register format.
SHDNTIMER Register (3Fh)
The SHDNTIMER register sets the timeout period from
when a shutdown event is detected until the device
disables the LDO and enters low-power mode.
Figure 45
shows the SHDNTIMER register format.
CTR12:CTR0—Shutdown Counter. This register counts
the total amount of elapsed time since the shutdown trig-
ger event. This counter value stops and resets to 0 when
the shutdown timeout completes. The counter LSb is 1.4s.
Figure 45. SHDNTIMER Register Format (Input/Output)
Figure 44. Timer Register Format (Output)
Figure 45
MSB—ADDRESS 3Fh LSB—ADDRESS 3Fh
THR 2 THR 1 THR 0 CTR 12 CTR 11 CTR 10 CTR 9 CTR 8 CTR 7 CTR 6 CTR 5 CTR 4 CTR 3 CTR 2 CTR 1 CTR 0
MSb LSb MSb LSb
Figure 44 MSB—Address 3Eh LSB—Address 3Eh
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: 175.8ms