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RN_it
Associate III
August 18, 2018
Solved

About voltage scaling 1, 2 ,3

  • August 18, 2018
  • 3 replies
  • 5237 views

Hello,

I am working on Power Reduction and we are using STM32F446RE Microcontroller.

In the RM i found this,

"the regulator output voltage (around

1.2 V) can be scaled by software to different voltage values (scale 1, scale 2, and scale

3 can be configured through VOS[1:0] bits of the PWR_CR register)."

so, my question is what is the regulator output voltage at scale 1, 2 and 3. is it less than 1.2 v? if i run my microcontroller at 80Mhz, then selecting scale 3 would reduce the power consumption ?

Thanks

    This topic has been closed for replies.
    Best answer by waclawek.jan

    > so, my question is what is the regulator output voltage at scale 1, 2 and 3.

    0690X000006BuegQAC.png

    > if i run my microcontroller at 80Mhz, then selecting scale 3 would reduce the power consumption ?

    Yes.

    3 replies

    T J
    Senior III
    August 19, 2018

    How about you test it and let us know ?

    if the core voltage is lower then the power will be lower.

    however, you must have approx 1.2V for everything to work correctly.

    ( 2 transistors in series need 1.1-1.2V to work correctly)

    the closer you get to that threshold, the more susceptible you will be to 'noise resets'

    waclawek.jan
    waclawek.janBest answer
    Super User
    August 20, 2018

    > so, my question is what is the regulator output voltage at scale 1, 2 and 3.

    0690X000006BuegQAC.png

    > if i run my microcontroller at 80Mhz, then selecting scale 3 would reduce the power consumption ?

    Yes.

    RN_it
    RN_itAuthor
    Associate III
    August 22, 2018

    Thanks for this @Community member​  and @Community member​