AnsweredAssumed Answered

MIFARE reader malfunctioning during EMC tests

Question asked by Nicola Magistrelli on Sep 14, 2018
Latest reply on Sep 24, 2018 by Nicola Magistrelli

Hello everybody,

 

I am facing an issue with the Mifare reader MFRC63002, when it is exposed to conducted disturbances by electromagnetic fields by using an absorbing clamp:

 

by setting the amplitude of the disturbance equal to 1V (AM 1KHz), when the frequency of the disturbance becomes a multiple of the quartz crystal frequency 27.12MHz the MFRC63002 chip stops working properly (the chip is not able to detect anymore the presence of a valid MIFARE classic or plus tag).

 

By analyzing the issue, we could see that when the problem occurs the following bits of the error register (addr. 0x0A), analyzed during the receiving phase, are set:

bit 4 MinFrameErr

bit 2 CollDet

 

The configuration registers of the transmitter and receiver are programmed with their default factory values.

Then, we modified the RxAna register (addr, 0x39) in order to reduce the Rx Gain and the RxThreshold register (addr. 0x37) in order to increase the MinLevel, but we did not get meaningful improvements.

 

Has anybody faced a similar problem like the one described above ? If yes, which countermeasures have been taken to solve or at least mitigate the issue?

 

Thanks in advance for your support.

 

Best regards,

Nicola Magistrelli.

Outcomes