ADC inputs

[pietrodcs]

Good morning

I have a schematic for the 52840 uP. I dump here

The ADC  inputs are fed with a 100K resistor. It is expecting a high impedance input. My question is : does it work?
For what I know out of other uP the analog input is not a high impedance and needs a much harder driving.
Suggest what to do here..

Thank You

Pietro

[Bendik Heiskel]

Hi Pietro,

The 100k source resistance should be OK, you just have to make sure the acquisition time is long enough for the voltage across the internal capacitor to stabilize. For 100k at least 10us is needed.

https://infocenter.nordicsemi.com/topic/ps_nrf52840/saadc.html?cp=5_0_0_5_22_0_0#concept_qh3_spp_qr

 

Best regards,

Bendik

[pietrodcs]

Ok.

Thank You

Pietro