STM32L432 dynamic VDD voltage change

[ikeken]

I'm developing a very power-saving product. The STM32L4 is a really great product for our application !

Usually I run the STM32L4 VDD at 1.8V. Operate at 3.3V only when end user configures it via USB.

The problem is that I want to switch the VDD voltage from the STM32 software.

 

Can I dynamically change STM32 voltage during runtime?

As long as I make the rate of voltage change very slow, I don't see anything wrong with that, since it is equivalent to just repeating the same amount of voltage change as a normal voltage ripple range. Is there any problem in thinking this way?

How fast [Volt / second] is it allowed to change the supply voltage ?

Thank you in advance !

[TDK]

Yes, you can change the voltage at will. You'll have to ensure the clocks and wait states are valid before switching. The bulk capacitors on VDD will prevent it from changing too quickly.

If it's meant to be low power, it may be easier to always use 1.8 V. You do not gain the benefits of 3.3 V unless you configure clocks higher, and switching between voltages increases code complexity with questionable benefits. But yes, you can do it.

[ikeken]

Thanks for the advice.
Excuse me, but I am designing a product and I want to make sure that I am guaranteeing this kind of usage as ST micro.
Can I understand it that way?

 

 

 

 

[TDK]

I'm unsure what you are asking.

[ikeken]

I am not familiar with this community, what does Guru mean?
I was not sure if you are an ST employer or if I should take your comment as an official ST one, so I would be glad to know your position. Thank you.

[TDK]

I'm not an official or employed by ST.

If you want to contact ST, file a support ticket.

https://ols.st.com/s/

 

[ikeken]

OK

Thank you for your comments.