MP2731 watchdog error and ADC readings

Battery Management
1

It seems that the ADC values do not update after a watchdog error is detected. It seems that the last readings during the error event are kept sticky in the registers. Even though a WD error occurs, charging will still operate (with reset settings), but the ADC readings are meaningless and not representing realtime data.

I also suspect that other error conditions may cause the same ADC behavior.

I cannot find any documentation reflecting this behavior. Please advice.

Thanks

2

I also have a followup question: Is there a way to “force” the safety timeout error to occur for development testing? It is rather tedious to have to wait 1 hour for the trickle charge and pre-charge timeout (by setting a low battery voltage), and even 5 hours for the constant current phase.

3

Hello,

Apologies for the delay of the response on this post. But to answer each question sequentially:

  1. To move forward with the ADC values not updating, I would like to ask the following questions:
  • If you try clearing the watchdog error flag, do the ADC readings resume?
  • If clearing the error flag doesn’t resume meaningful ADC reading values, try a soft reset.
  • Checking for other error states may deem this value freezing behavior as a byproduct.
  1. I suppose if you wanted to speed up this safety timeout error, using a lower threshold for trickle charging and/or pre-charge should speed up this transition. You could also adjust the charge timer settings via a resistor change or register config settings.

I look forward to hearing from you again to see if there is any progress in your debugging.

Best,
Krishan