LSI in Backup Domain on STM32H735.

[DDuque]

Datasheet and Reference Manual have contradictions about the LSI Power.

Information from Datasheet:

The RTC is functional in VBAT mode and in all low-power modes when it is clocked by the

LSE. When clocked by the LSI, the RTC is not functional in VBAT mode, but is functional in

all low-power modes.

Power diagram in Datasheet and Reference Manual:

Is this picture wrong?

[Tesla DeLorean]

Not checked, it used to be the case for older STM32 families, but would make sense if it were moved into the backup domain. Likely to have a higher current draw.

Should be able to double check by watching the RTC tick getting bigger over a STANDBY. Will flag this post. @Imen DAHMEN​  @Amel NASRI​ 

[Amel NASRI]

Hi @DDuque​  & @Community member​ ,

Thanks for bringing this to our attention.

Indeed, it is a typo already fixed in RM0399 & RM0433 but we need to do the same in RM0468 & RM0455.

The correction is to move LSI from Backup Domain to VDD Domain.

A request is tracked internally to make this update.

-Amel

[DDuque]

Hi @Amel NASRI​ ,

Thank you for the update.

Just one note: Figure 14 on DS13312 Rev 2 has the same issue.

[Amel NASRI]

Good catch @DDuque​ . Unfortunately the same error was propagated to almost all datasheets as well as Hardware getting started application notes.

I'll take care to report this in order to make the updated where required.

-Amel