LSI frequency range for STM32F303CC

[Gahlen Feld]

Posted on February 13, 2018 at 13:16

The current data sheet for the STM32F303CC (DocID023353 Rev13) shows on page 80 the characteristics of the LSI oscillator.

Its frequency starts from min. 30kHz to typical 40 and max. 50 kHz (all at 3.3V in the max. allowed temperature range).

In the same document on page 93 there is a footnote regarding the LSI frequency range to vary from 30 to 60kHz.

Now I am a little bit confused what maximum value for the LSI frequency is the right one for my watchdog timeout calculations, 50kHz or 60kHz max? (and under which circumstances this frequency appears)

People at ST, please help me in finding the correct value.

Thank you in advance,

Gahlen

#iwdg #frequency-range #datasheet-inconsistency #lsi

[Imen.D]

Posted on February 14, 2018 at 11:32

Hello

Feld.Gahlen

,

The

LSI frequency

Max is

50 kHz.

So, the Table LSI oscillator characteristics in page 80 is correct (Max is

50 kHz

), and t

hefootnote (in thepage 93) re

garding the LSI frequency should be updated to '

frequency can vary from 30 to 50 kHz'.

Thanks for bringing this confusion to our attention. I forwarded this issue internally to the appropriate team for correction in the coming datasheets.

Best Regards,

Imen

[Andrew Neil]

Posted on February 14, 2018 at 13:07

Imen D wrote:

t

he footnote (in the page 93) re

garding the LSI frequency should be updated to '

frequency can vary from 30 to 50 kHz'.

No:  it is better not to duplicate information like this! It just leads to inconsistencies - like this!

It would be better for the note to simply refer to where the frequency range is defined.

[waclawek.jan]

Hi @Imen.D ,

The current STM32F303CC DS9118 Rev 14 still has the incorrect "60 kHz" footnote.

I see it also in other 'F3 and 'F0 datasheets.

JW