Temperature Measurement
33
SLUUBE8 – September 2018
Copyright © 2018, Texas Instruments Incorporated
Functional Description
2.3
Temperature Measurement
The fuel gauge typically measures battery temperature via its TS input to supply battery temperature
status information to the gas gauging algorithm and charger-control sections of the gauge. Alternatively, it
can be configured to use an internal on-chip temperature sensor or receive temperature data from the
host processor. See
for specific information on configuration options.
Regardless of which temperature configuration is used, the host processor can request the current battery
temperature by reading the
Temperature()
, and for internal temperature,
InternalTemperature()
.
The external thermistor circuit requires the use of an 10K NTC 103AT-type thermistor.
2.3.1 Overtemperature Indication
2.3.1.1
Overtemperature: Charge (OT Chg)
If during charging,
Temperature()
reaches the threshold of
OT Chg
for a period of
OT Chg Time
, and
Current()
>
Chg Current Threshold
, then the
BatteryStatus()[OTC]
bit is set. When
Temperature()
falls to
OT Chg Recovery
, the
BatteryStatus()[OTC]
bit is cleared.
If
OT Chg Time
= 0, then the feature is completely disabled.
2.3.1.2
Overtemperature: Discharge (OT Dsg)
If during discharging,
Temperature()
reaches the threshold of
OT Dsg
for a period of
OT Dsg Time
, and
Current()
≤
–
Dsg Current Threshold
, then the
BatteryStatus()[OTD]
bit is set. When
Temperature()
falls
to
OT Dsg Recovery
, the
BatteryStatus()[OTD]
bit is cleared.
If
OT Dsg Time
= 0, then the feature is completely disabled.
2.3.2 Undertemperature Indication
2.3.2.1
Undertemperature: Charge (UT Chg)
If during charging,
Temperature()
reaches the threshold of
UT Chg
for a period of
UT Chg Time
, and
Current()
>
Chg Current Threshold
, then the
BatteryStatus()[UTC]
bit is set. When
Temperature()
rises
to
UT Chg Recovery
, the
BatteryStatus()[UTC]
bit is cleared.
If
UT Chg Time
= 0, then the feature is completely disabled.
2.3.2.2
Undertemperature: Discharge (UT Dsg)
If during discharging,
Temperature()
reaches the threshold of
UT Dsg
for a period of
UT Dsg Time
, and
Current()
≤
–
Dsg Current Threshold
, then the
BatteryStatus()[UTD]
bit is set. When
Temperature()
rises
to
UT Dsg Recovery
, the
BatteryStatus()[UTD]
bit is cleared.
If
UT Dsg Time
= 0, then the feature is completely disabled.
2.4
Battery Condition Warnings
2.4.1 Battery Low Warning
The bq34210-Q1 device can indicate, and optionally trigger an alert signal, when the battery voltage falls
below a programmable threshold. This feature is disabled if
Battery Low Time
is set to 0.
NOTE:
If
Battery Low Time
is set to 30 seconds or higher, the device may initiate an automatic
offset calibration during the time window, resulting in the BATLOW signal being delayed
approximately an additional 15–20 seconds beyond the
Battery Low Time
setting.
