Temperature Protections
30
SLUUBD3D – September 2015 – Revised September 2018
Copyright © 2015–2018, Texas Instruments Incorporated
Protections
Status
Condition
Action
Recovery
SafetyStatus()[UTD]
AND
Temperature()
≥
UTD:Recovery
SafetyStatus()[UTD]
= 0
OperationStatus()[XDSG]
= 0
Class
Subclass
Name
Type
Min
Max
Default
Unit
Protections
UTD
Threshold
I2
–400
1500
0
0.1°C
Protections
UTD
Delay
U1
0
255
2
s
Protections
UTD
Recovery
I2
–400
1500
50
0.1°C
3.7.5 Overtemperature FET Protection
The device has an overtemperature protection to limit the FET temperature.
NOTE:
This feature is only available when using the bq76930x or bq76940x device: There is only
one external TS available in the bq76920 and this is used for cell temperature.
Status
Condition
Action
Normal
FETTemperature()
<
OTF:Threshold
SafetyAlert()[OTF]
= 0
Alert
FETTemperature()
≥
OTF:Threshold
SafetyAlert()[OTF]
= 1
BatteryStatus()[TDA]
= 1,
[TCA]
= 1
Trip
FETTemperature()
≥
OTF:Threshold
for
OTF:Delay
duration
SafetyAlert()[OTF]
= 0
SafetyStatus()[OTF]
= 1
BatteryStatus()[OTA]
= 1
BatteryStatus()[TDA]
= 0, [TCA] = 0
OperationStatus()[XCHG][XDSG]
= 1,1 if
FET
Options[OTFET]
= 1
Recovery
SafetyStatus()[OTF]
AND
FETTemperature()
≤
OTF:Recovery
SafetyStatus()[OTF]
= 0
BatteryStatus()[OTA]
= 0
BatteryStatus()[TDA]
= 0,
[TCA]
= 0
OperationStatus()[XCHG][XDSG]
= 0,0
3.8
Precharge Timeout Protection
The device can measure the precharge time and stop charging if it exceeds the adjustable period.
Status
Condition
Action
Enable
Current()
>
PTO:Charge Threshold
AND
ChargingStatus()[PCHG]
= 1
Start PTO timer
SafetyAlert()[PTOS]
= 0
Suspend or Recovery
Current()
<
PTO:Suspend Threshold
Stop PTO timer
SafetyAlert()[PTOS]
= 1
Trip
PTO timer >
PTO:Delay
Stop PTO timer
SafetyStatus()[PTO]
= 1
BatteryStatus()[TCA]
= 1
Charging is not allowed.
Reset
SafetyStatus()[PTO]
= 1 AND
(Discharge by an amount of
PTO:Reset
)
Stop and reset PTO timer
SafetyAlert()[PTOS]
= 0
SafetyStatus()[PTO]
= 0
BatteryStatus()[TCA]
= 0
Charging is allowed.
Class
Subclass
Name
Type
Min
Max
Default
Unit
Protections
PTO
Charge Threshold
I2
–32768
32767
2000
mA
Protections
PTO
Suspend Threshold
I2
–32768
32767
1800
mA
Protections
PTO
Delay
U2
0
65535
1800
s
Protections
PTO
Reset
I2
–32768
32767
2
mAh
