BQ27220: bq27220 OTP program

Hi Wyatt Keller:

          The communicate between EV2400 and bq27220 are ok, I have resolved it.

• but there is other question please help me.
• /cfs-file/__key/communityserver-discussions-components-files/196/to-ti_5F00_20210520.pdf

Hi,

Full Charge Capacity is updated by the gauge FW while discharging, we should not change it. It will be set to Learned Full Charge Capacity at first, you just need to make sure Design Capacity is set to the actual value.

Best Regards,
Abraham

Hi Ti:

        Thanks you for your reply, But I still unknow that I read out the design capacity isn't the value that I programed in the fuel gauge, what is the root cause? (Please refer to the pdf which upload yesterday)Please explain detail.

thanks  a lots!

Hi Ti :  

         thank you for your reply! 

there is another question for you ,please refer to the attached PDF file.

thanks!

/cfs-file/__key/communityserver-discussions-components-files/196/20210602_5F00_to_5F00_ti.pdf

Hi ti:

      BQ27220 SPEC.(bq27220 Single-Cell CEDV Fuel Gauge) say "Supports a Low-Value (10-mΩ) External Sense Resistor" , but my question which i posted yesterday that the "sense resister"on my EVM is 5-mΩ, I  don't know if the BQ27220’s "sense resister" can’t support 5-mΩ?

Hi Ti

    Thank for your reply,I describe my question again,the original sense resistor on my EVM is 10mΩ, Now I change to 5mΩ,and then calibtrate cc offset,board offset,temp,current,voltage in BQSTUDIO calibration page,sametime change fcc capacity, design capacity, design capacity in gas gauge item, finish above operation ,create *.ot.fs file in golden image page ,and progam BQ27220 OTP using smartflash ,after program successfully ,I connect EVM via EV2400 and then open BQSTUDIO check the parameter which I calibrated and changed, except current incorrect, the other parameter all ok. I recheck and recalibrate over 2 twice, but the result is same as above. I don't know what is the root reason can you help me?please details. very thanks!

Add describe :The wrong current value matches the original current value of 10mΩ.

Is the current value correct after calibrating with 10mΩ?

Hi Ti:

    BQ27220 pre-calibrate sense resistor is 10mΩ, no need calibrate the current with 10mΩ the current is correct. after calibrate whit 5mΩ and then program to OTP, test the current is incorrect, change 5mΩ to 10mΩ the current is correct. 

Hi Ti:

          thank you for your reply! About above question I think I capture some picture to describe it is easy to analyse.

I don't know what is the root reason, please give me a help. thanks!

/cfs-file/__key/communityserver-discussions-components-files/196/20210604_5F00_to_5F00_ti.pdf

Hi,

Did you change the values in those three? Those are for OTP programming

Hi ti:

      I only change gas gauge some parameters and calibration five parameters. how to save the calibrated the current in OTP?I can't find cc gain and cc delta in calibration(present otp). can you detail this operation? because the project are very urgent ,it is only current calibrated not pass, the other parameters are ok. very thanks!