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Associate II
June 15, 2024
Solved

power consumption vs. clock rate 32L4xx ?

  • June 15, 2024
  • 2 replies
  • 1996 views

hello all;

i wondered if there are good guidelines for power consumption vs. clock, and, how low can the processor clock run? complex, i think, especiallly if one needs to run certain peripherals like ADC, or i2c... thanks!

Best answer by Andrew Neil

Very often, the lowest power consumption is better achieved by running the processor at full speed so that it can get stuff done quicker, and then sleep longer.

Look at the peripherals' facilities to run without CPU intervention...

Only run the peripherals when actually needed ...

2 replies

Andrew Neil
Andrew NeilBest answer
Super User
June 15, 2024

Very often, the lowest power consumption is better achieved by running the processor at full speed so that it can get stuff done quicker, and then sleep longer.

Look at the peripherals' facilities to run without CPU intervention...

Only run the peripherals when actually needed ...

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.
LohiAuthor
Associate II
June 15, 2024

yep, true...i did a military system some years ago, and used an 8-bit CMOS processor to detect s 'trigger' event, and then wound up a big CPU with math coprocessor, which ran for 30 seconds, a couple of times per day...so, indeed, valid approach, run like crazy, sleep...kind of like a cat!

 

Thx

 

AScha.3
Super User
June 15, 2024

Hi,

looking at ds of your chip might give information...

AScha3_0-1718442636036.png

also for each peripherals..

AScha3_1-1718442729702.png

+Check with power calculating tool in Cube, if you prefer ...

AScha3_2-1718442962717.png

 

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LohiAuthor
Associate II
June 15, 2024

Ja, so es gent....I'm quite ill, at the moment, not able to view the 500 pages on the computer, and, about 2 minutes after posting, had a "Duh!" moment, so thanks for telling me where to RTFM!

15 years of AE experience, RTFM comes often to mind, so thanks for the polite response.