STM32G4 comparator source sink current

MMala.3 · ‎2024-03-28

Hi

Is there any info available regarding source sink current of analog comparators on the STM32G4 series.

The datasheet doesn't contain any info on this although the drive current of Opamps is mentioned as 500uA.

TIA

Peter BENSCH · ‎2024-03-28

Now, after a look at RM0440, section 24.3.1, you will realise that the (digital) output of the comparators is not routed directly to the pins, but via a (digital) polarity switch. Only then is the signal available at the GPIO, which results in the current carrying capacity of a GPIO.

[edit] I forgot to point out that the respective COMPx_OUT is an Alternate function output, which is visible in fig. 25 as input of the digital GPIO driver. [/edit]

Does it answer your question?

Regards
/Peter

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View solution in original post

Peter BENSCH · ‎2024-03-28

Now, after a look at RM0440, section 24.3.1, you will realise that the (digital) output of the comparators is not routed directly to the pins, but via a (digital) polarity switch. Only then is the signal available at the GPIO, which results in the current carrying capacity of a GPIO.

[edit] I forgot to point out that the respective COMPx_OUT is an Alternate function output, which is visible in fig. 25 as input of the digital GPIO driver. [/edit]

Does it answer your question?

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

MMala.3 · ‎2024-03-28

Hi

Is it correct to say that the comparator output source sink current spec is same as the GPIO source sink capability.

The GPIOs (general purpose input/outputs) can sink or source up to ±8 mA, and sink or
source up to ± 20 mA (with a relaxed VOL/VOH).

This is stated in the STM32g491 datasheet Pg114.

TIA

Peter BENSCH · ‎2024-03-28

Yes.

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