Buffered DAC or OPAMP max current ouput?

[Bertrand1]

Hello,

I don't find on the STM32H730ZB datasheet a clear information about the maximum current output for the DAC ( with or without a OPAMP in follower). I plan to drive a LED from 100µA to 10mA maximum.

Today, I have an externaI op-amp & mosfet but I would like to reduce the footprint of my board and the BOM cost

Thanks

Bertrand

[Peter BENSCH · Accepted solution]

In DS13315 (Section 6.3.24) you won't find the current directly in the DAC characteristics, but the minimum load resistance to VSSA (5kohms) or VDDA (25kohms).

The maximum drive current of the integrated opamp is 500µA.

As a result, an LED cannot be controlled directly with your desired currents, neither with the DAC nor an internal opamp as a buffer.

But you can replace the external opamp with the internal one to control the external FET?

If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.

Good luck!

/Peter