Clarification on Voltage Scale Selection for STM32WB55MMG at 32 MHz Clock

[SaiGaneshCS]

Hi,

I am working with the STM32WB55MMG and have configured the system clock to run at 32 MHz. Could you please confirm which Voltage Scale setting is required for this configuration?

As per the reference manual,

• Voltage Scale 1 supports up to 64 MHz.
• Voltage Scale 2 supports up to 16 MHz.

Since 32 MHz exceeds the limit of Scale 2, does STM officially recommend using Voltage Scale 1 at 32 MHz?

Additionally, if there are any recommended low-power optimizations for running at 32 MHz, please advise.

Thank you.

Best regards,
[Sai Ganesh CS]

[STTwo-32]

Hello @SaiGaneshCS 

Yes, for the 32MHz clock, you should use the Voltage Scale 1 (VOS 1). 

For the Power optimization, I suggest you try to stay in the deepest low power possible as long as you can (to reduce the power consumption). Also, you can disable all the peripheral that you are not using and put all unused GPIOs to the analog input mode. More details available here also.

Best Regards.

STTwo-32

[SaiGaneshCS]

Hello,

What is the expected change in current consumption when the clock frequency is reduced from 32 MHz to 16 MHz?

 

Thanks and Regards,

Sai Ganesh CS

[STTwo-32]

When the clock frequency is reduced from 32 MHz to 16 MHz, the current consumption is expected to decrease. To have exact values. You should perform test on both cases.

Best Regards.

STTwo-32