BQ28Z610: XCHG and XDSG bits are ON when there are no protection flags set

Hello Victor,

Could you explain what type of test/situation was causing the protection to become active and attach the data of when the flag becomes set . Also which protection register is flagging and could you attach your data command register as a .gg.csv file.

Thank you,
Alan

I don't know how it happened, as I wasn't running any tests, just writing drivers, but for some reason the temperature read as -273 ºC (don't remember the exact number right now), so the UTD protection got triggered. For some reason the temperature reading register was at 0x00, so re-enabling the internal thermistor untriggered that one.

Right now, as you can see from the picture, none of the flags are being triggered.

I am having trouble getting the whole image, for some reason the device image option is not on my BQstudio program anymore.

7343.bq28z610.gg.csv

Here is the csv file

Hello Victor,

After reviewing your UTD register you don't have any unusual values, your Internal Temp Offset is at -5 and default is 0 but that shouldn't be effect. However it seems that your internal thermistor is working good and your external thermistor is not which could hint to you using the wrong values for your thermistor. I would stick to the same values as seen on the EVM board "Semitec 103AT-2". Which thermistor are you using?


Thank you,
Alan

Right now I am not using an external thermistor. If I just put a 10k resistor should it be able to simulate a good temperature?

Hello, 

You cannot use a standard resistor, you must use a thermistor. I recommend using the thermistor that is used in the BQ28Z610 EVM. 

Regards, 

Jonny.  

Hello Victor, 

Are you using a EVM or a custom made PCB? Could you try to use another EVM and program your setting with your current registers. If you are not using a external thermistor and your internal thermistor is not working another an external thermistor would not fix the internal thermistor. Another method to test to see if your hardware(internal thermistor) is not working is by using the default setting on the registers expect for these values below and seeing if your temperature values are acceptable. 

-Design Capacity, Design Voltage, Charge Term Taper Current, Discharge (Dsg) Current Threshold, Charge (Chg) Current Threshold, Quit Current and Term Voltage

Thank you,
Alan

I'm working on a custom PCB. The internal thermistor is working correctly, measuring right now a reasonable temperature, near room temperature.

I just checked tying a 10k resistor just to "simulate" a thermistor and it read around 25C. Still, no changes on the XDSG and XCHG bits.

The internal thermistor IS working.

Hello Victor, 
I would  
That sounds good and it seems like your internal resistor is working now. I would follow the EVM to upbring your board and make sure you have all the values below are configurated correctly. 

EVM documentation: 
https://www.ti.com/lit/ug/sluube3/sluube3.pdf?ts=1741634827635&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FBQ28Z610EVM-532

Data memory needed resistor: 
Design Capacity, Design Voltage, Charge Term Taper Current, Discharge (Dsg) Current Threshold, Charge (Chg) Current Threshold, Quit Current and Term Voltage 

Thank you,
Alan

So I tried using another BQ28, copied the Data Memory, and dumped it back into the one that-s not working.

The problem persists.

Trying some stuff, when FET_EN is off, I pressed on the DSG_FET_TOGGLE and CHG_FET_TOGGLE which seem to be for testing the FETs and those worked. But when I put FET_EN on again, XDSG and XCHG are set again.

Hello Victor,

To confirm that you tired to recreate your issue on a EVM and still didn't work? If that is the case than it would hint that your firmware is the issue and I would look at your parameters in the dataflash to see what you set them too. If you didn't get a chance to upload your data flash parameters than I would like a chance to review your schematics. Either ways in the mean time set your values in data flash to default and only update critical flash values and use the command tab to manually toggle the fets on your board.

Thank you,
Alan