Max Output drive current of Analogue Peripherals when VDD <> VDDA

[Tian]

Hi.  I'm designing a battery powered device that use 1.8V for the MCU core and 3V for VDDA to drive the opamps and comparators.   

I would like to use the output of an opamp / comparator to power a small sensor at 3V- enabling me to switch it on/off via firmware without adding additional components. It is not clear in the data sheet what the maximum I_DDA current is that can be supplied by the opamp / comparator output.

 

Any advise would be appreciated.

Thanks

  

[Peter BENSCH]

Welcome @Tian, to the community!

If I understand your question correctly, you are looking for the maximum output current of the opamp of an STM32G4 to supply your external circuit?

If that is correct, you will find the information in the OPAMP characteristics of the respective data sheet. For the STM32G4, the maximum is 500µA, in PGA mode 270µA.

Does it answer your question?

Regards
/Peter

[waclawek.jan]

... and the comparator output is a normal GPIO/AF, so for that, the GPIO section's data from datasheet apply.

Those are significantly higher currents, so you may want to use COMP rather than OPAMP.

JW