This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

PPK: Calibration sequence question

When the PPK calibrates and turns off the DUT, does the nRF52832 on the PPK disconnect from the External DUT lines? My DUT has a LOT of capacitance on it, and it takes several seconds to fully discharge the caps after power has been removed.

My question is: Does sending the RTT_COMMAND.RTT_COMD_DUT 0 (line 1143 in ppk.py) actually disconnect the External DUT lines from the ADC on the nRF52832? Will a voltage on the External DUT lines during PPK Calibration throw off the calibration?

  • The calibration should not be affected by this.

    The ADC lines are disconnected through an analog switch when the PPK asks to power off the external DUT. We haven't seen any leakage through this switch, but if the DUT for some reason will have a higher voltage than the PPK is supplying, there might be some reverse leakage.

    In your case, this will not happen.

Related