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BQ78350-R1: Discharge FET turns off with high current load

Part Number: BQ78350-R1
Other Parts Discussed in Thread: BQSTUDIO, , BQ76930

I'm able to attach low current loads without an issue, but as soon as I attach my 10A load the DSG bit in operationstatus goes low. I turned off all protections, but there are so many moving parts, maybe I'm missing something? I'll attach a screenshot of the bqstudio registers view when I have the two loads attached (notice that the DSG bit is green for the high current load [fig1] and red for the low current load [fig2]) and I'll attach data memory>settings [fig3] view to show my current settings. Thanks for your help.

Figure 1: High Current Load

 

 

Figure 2: Low Current Load

 

 

Figure 3: Settings

  • Hi,
    Your post has been assigned to one of our BMS experts.
    Regards,
    Bethlehem
  • Hi JP,
    The hardware protections of the bq769x0 used with the bq78350-R1 can not be turned off. The levels are set by the bq78350-R1 through data flash settings.
    The bq769x0 default OCD level is 8 mV. If you use a 1 mOhm sense resistor 10A will give a 10 mV level and trip OCD. In the bq78350-R1 this shows up as AOLD, if the timing is right you may see that status set. To avoid the protection, set the AOLD Threshold and delay value appropriately. Note that the technical reference manual will point you to the bq76930 data sheet for the register definition to be stored as Threshold and delay.
  • Oh man, I was so close to figuring it out. Thanks again, WM. Always helpful.