I'm designing an application with the PN7462 and its DPC. Currently I have 3 gears implemented with the NFC cockpit. Using an oscilloscope and an EMVCo TestPICC I can see the gears switching up and down when changing the distance between the NFC antenna and the TestPICC. So far, so good.
However, when I switch on the field using the cockpit, I see the following waveform (on DC-Out of the TestPICC which is at z=0cm):
It seems that the DPC starts at the lowest gear with the highest voltage, possibly harming the PN7462's output stage. Certainly, this is because I set the DPC-Control Byte (at 0x201352) to 0x13 (=Start Gear 1, DPC enabled, Gear Step 1).
When reading AN11742 it seems to me, that the DPC Control byte has to be 0x33 as I have 3 gears active. However, in this case the DPC does not work at all. Here the DPC stays at gear 0 all the time, regardless of how high the AGC-Value rises.
So how to start the DPC at gear 3 at power on? What do I get wrong?
Thank you for any help!
Solved! Go to Solution.