Hello Everybody,
I faced a problem in PN532 that after a long time (reading cards) PN532 hangs on and does not respond even to the first SamConfiguration command sent over SPI. After sending the Reset signal the situation also doesn't change. PN532 may start working normally after some time or after power on/off.
The schematic is as AN10609_2 recommends. And two more details - the PCB is covered with polyurethane and when we open the potting with the 35 - 40 pins, PN532 starts working normally. Also, the VBAT voltage is in the 3.2 - 3.4 V range. Could potting or voltage range be an issue?

Best regards,
Kirill