Associate III

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STM32 lowest current?

Forum|Forum|8 years ago
December 7, 2017
9 replies
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Posted on December 07, 2017 at 16:00

Which STM32 has the actual lowest running current consumption (active from flash)?

#stm32-lowest-current

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Best answer by Andrew Neil

Posted on December 07, 2017 at 16:57

http://www.st.com/en/development-tools/st-mcu-finder.html

http://www.st.com/content/st_com/en/product-selector.html

- indeed there is a column for mA/MHz !

Super User

Posted on December 07, 2017 at 16:12

define, 'running' ?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.

Mich1Author

Associate III

Posted on December 07, 2017 at 16:18

called 'run mode' in ST datasheet

Super User

Posted on December 07, 2017 at 16:32

Well, you can get mA/MHz figures for the core from the datasheets - but the actual running current of the entire chip will depend on what peripherals you use, and how you use them ...

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.

Mich1Author

Associate III

Posted on December 07, 2017 at 16:49

I hoped ST could advise a component for a new design but it is true that I can read all STM32 datasheets.

Super User

Posted on December 07, 2017 at 16:54

I guess they should be able to tell you the lowest mA/MHz number - but, as noted, there's a lot more to it than just that!

Have you spoken to you local FAE and/or Distributor?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.

Mich1Author

Associate III

Posted on December 07, 2017 at 17:08

Unfortunatly, only LDO mode is indicated.

From the STM32L476: 100 Î¼A/MHz run mode (LDO Mode) 39 Î¼A/MHz run mode (@3.3 V SMPS Mode)

But is a good start, thanks a lot.

Senior III

Posted on December 11, 2017 at 09:04

Hello,

Regarding STM32 MCUs, which consume the smallest current consumption in RUN mode, I would like to highlight two families:

http://www.st.com/en/microcontrollers/stm32l0-series.html?querycriteria=productId=SS1817

based on Cortex-M0+ and

http://www.st.com/en/microcontrollers/stm32l4-series.html?querycriteria=productId=SS1580

based on Cortex-M4F. These two families are defenitely the best in whole STM32 portfolio in terms of current consumption (including RUN mode).

In both families I would propose to focus on devices, which have small amout of resources, especially memory (Flash, SRAM), as this factor has impact on current consumption. In STM32L0 family such devices are

http://www.st.com/content/ccc/resource/technical/document/datasheet/42/c0/ab/e5/71/7a/47/0b/DM00206508.pdf/files/DM00206508.pdf/jcr:content/translations/en.DM00206508.pdf

. Theys can consume the current down to 76 uA/MHz in RUN mode. In STM32L4 family by using the same approach we should select

http://www.st.com/content/ccc/resource/technical/document/datasheet/group3/83/b3/60/f6/b1/cc/47/7e/DM00257211/files/DM00257211.pdf/jcr:content/translations/en.DM00257211.pdf

. Here the smallest expected consumption is 84 uA/MHz in RUN mode.

Additionally some of STM32L4 MCUs support a SMPS, which allows to bypass the embedded LDO and reduce the consumption even more. For example

http://www.st.com/content/ccc/resource/technical/document/datasheet/f7/a0/fc/27/24/4e/4f/3f/DM00257192.pdf/files/DM00257192.pdf/jcr:content/translations/en.DM00257192.pdf

, with SMPS, will consume only 36 uA/MHz in RUN mode.

Regards

Szymon