TPS659037: Why the voltage of SMPS12 of TPS6590379ZWSR fluctuates?

Akira Tanigawa

Part Number: TPS659037
Other Parts Discussed in Thread: AM5728

Tool/software:

I use a TPS6590379ZWSR with AM5728.

The SMPS1 and SMPS2 are connected parallely as the datasheet.

I found the output voltage of SMPS12 fluctuates after system starts up.
Refer to the following figure. (Yellow : SMPS1_SW Green : SMPS2_SW Pink : SMPS12 voltage)

Only the SW2 sometimes stop after the system starts up.
I don't know that's why the SMPS12 (VDD_MPU) fluctuates but the VDD_MPU isn't stable.

But I can use the system with no problem.
Is this phenomenon correct?

24 days ago

0 Phil Yi40 23 days ago

TI__Mastermind 38550 points

Hi Akira,

I believe the SMPS12 (VDD_MPU) fluctuate is normal since it should be caused by MPU's different working mode; the PMIC has higher (1.25V) when the MPU is working in active mode; the voltage could be lower (1.09V) when the MPU working in low power mode.

For more details, a new e2e post with the MPU part number AM5728 can help from Apps engineer of the device.

Thanks!

Phil

0 Akira Tanigawa 20 days ago in reply to Phil Yi40

Prodigy 60 points

Dear Phil

I understood your answer.

Thank you.

Akira

0 Phil Yi40 19 days ago in reply to Akira Tanigawa

TI__Mastermind 38550 points

Hi Akira,

Please help to close the ticket.

Thanks!

Phil

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TPS659037: Why the voltage of SMPS12 of TPS6590379ZWSR fluctuates?