BQ40Z50-R1: overtemperature protection problem

Sherry Liang

Part Number: BQ40Z50-R1
Other Parts Discussed in Thread: BQSTUDIO

Dear team,

In the firmware, the OTC has been set to 45 degrees, the delay is 2s, the recovery is 40 degrees, and the OTD is 55 degrees, the recovery is 50 degrees. The temperature reaches 48 degrees when charging, but the battery can still be charged, and the charging current has no change, that means over temperature protection does not work. The output of the CHG pin has been about 23V. What is the reason? Why is the threshold set but no over temperature protection? Is it wrong to set up?

Could you please help to answer this question?

Thank you very much!

Sherry

over 6 years ago

0 Matt Sunna over 6 years ago

TI__Guru* 81034 points

Hi Sherry,

Can you please send us your data memory settings (.gg file)? You can export this from the bqStudio Data Memory screen. This might help us determine if there is anything that is not set up correctly in the settings. Make sure you have configured the FET Options setting in Data Memory to set the OTFET bit to '1' if you want the CHG FET to be disabled when there is an over-temperature fault.

When the temperature reaches 48 degrees, can you tell me the what you are reading in the SafetyStatus(), SafetyAlert(), BatteryStatus(), and OperationStatus() registers? The behavior of these registers during a over-temperature fault condition should follow the behavior described in Section 2.9 of the TRM (Technical Reference Manual).

Also, please let us know how you are measuring and controlling the temperature. Are you reading 48 degrees from the gauge internal or external temp registers? Have you performed temperature calibration on the device?

Best regards,
Matt

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BQ40Z50-R1: overtemperature protection problem