TPS6521825: LP873347 and TPS6521825: Will either PMIC cause voltage spikes when shutting down?

adevries

Part Number: TPS6521825

Hello,

I am considering using the LP873347 and TPS6521825 to power an i.MX 8M Mini processor. A previous PMIC I was evaluating for this purpose has the weird quirk where, when the PMIC was commanded to turn off, it would cause a spike on the input voltage rail (the rail supplying power to the PMIC). I wrote about this issue here: https://community.nxp.com/t5/Power-Management/PF8200-VIN-spikes-when-shutting-down/m-p/1251606. I'm also attaching an oscilloscope screenshot of the issue.

This "quirk" has caused me a number of headaches, so before I choose a new PMIC, I figured I should ask: Do either the LP873347 or TPS6521825 exhibit any behavior like this? Are there any situations where commanding either PMIC to turn off will backfeed current into the input voltage rail? Or cause a voltage spike on the input voltage rail?

Thanks

over 4 years ago

+1 Layne J over 4 years ago

TI__Genius 12735 points

Hello,

I am not aware of this behavior existing for either device although it would be best to test an EVM for each device to make sure there will not be any issues in your system.

Best regards,

Layne J

0 adevries over 4 years ago in reply to Layne J

Intellectual 955 points

Hi Layne,

Thanks for the reply. That is my plan as well. I wouldn't expect most PMIC devices to exhibit this behavior, but I will be testing the EVMs to make sure.

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TPS6521825: LP873347 and TPS6521825: Will either PMIC cause voltage spikes when shutting down?