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nRF52840 input circuit question

Dear Engineers! have a questions about the Input circuit of nRF52.

I have to monitor the signal LEVEL from some sensor. The signal can be Positive or Negative current, so , the input of nRF52 should be internally pulled to (+) or (-) use int. resistors of typ. 13k according to the GPIO spec.

May questions:

  1. is it possible to use GPIO UP/DN resistors in case of COMP (comporator) module ? or these GPIO resistors auto disconnected ?
  2. is it possible to use SAADC Rladder PU/PD Resistors (160k) of RESP (+) if I will use SAADC at the same time with the COMP module ?
  3. the COMP module has internal programmable Current ISOURCE of 2,5uA / 5uA and 10uA, so what happined in case of using SAADC and COMP at the same time ? ISOURCE current has negative direction ?

thank you!

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