nRF5340 VDD 1.8V

[ahrnicek]

Hi, 

I have some of peripherals at 1.8V and some at 3.3V that I'd like to run off the nRF5340. Is there a way to selectively set which interface is in a specific voltage domain? I think I can connect VDD to 1.8V which would make the GPIO voltage domain also 1.8V. The VDDH would need something higher though - 3.3V. I'm not using USB so I think I can leave VUBS disconnected/floating. 

Is there a better way to go about this that will either reduce power consumption or simplify the design? It would be really nice to avoid using level shifters... 

Thank you,

Andy

[Kenneth]

I don't see any other way than having some level shifters really. All GPIO's run on the same power domain, and if you feed voltage higher than VDD+0.3V (=2.1V in your case) on a GPIO you will trigger the internal ESD diodes, which will likely cause the GPIOs to experience EOS damage over time.

Kenneth

[ahrnicek]

Okay. I thought it was worth asking. Thank you.

Andy