TPS65217: LDO4 didn't go to LOW during PMIC(TPS65217D) RESET

Nicky Lim

Genius 3195 points

Part Number: TPS65217

Hello,

Customer made circuit as below, and under test.

During RESET TPS65217D, all power rail go to 0V, but only LDO4 doesn't go to 0V.

It remains as around 2.8V.

It happens even pull down RESET pin more than 1 seconds.

Could you check and let me know why LDO4 doesn't go to 0V while RESET?

Regards,

Nicky

over 6 years ago

0 Brian Berner over 6 years ago

TI__Mastermind 30260 points

Nicky,

Can you verify that no other rails are muxed to the same place as LDO4 and there are no leakage paths that allow 2.8V to be present on LDO4 through the processor?

2.8V is approximately a diode drop below 3.3V, so my guess would be another rail is powered on and providing power to the processor and this voltage is showing up on LDO4.

If you can isolate LDO4 and re-test this would help the debug process move along faster.

0 Ajeya Anand over 6 years ago in reply to Brian Berner

Intellectual 365 points

Thanks Brian
I am facing the similar problem. I am seeing 1V instead of 2.8V.
I did not get how does the powering the procecssor through another rail show up on LDO4. Kindly explain .

0 Brian Berner over 6 years ago in reply to Ajeya Anand

TI__Mastermind 30260 points

AA,
You appear to have created a new thread (e2e.ti.com/.../651787) for your follow-up question and answered by a few people already.

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TPS65217: LDO4 didn't go to LOW during PMIC(TPS65217D) RESET