AnsweredAssumed Answered

PN532 - no Field

Question asked by Michael Reikersdorfer on Jun 21, 2017
Latest reply on Apr 19, 2018 by Michael Reikersdorfer

I use the PN532 to read data from a JCOP Card.

My problem is, that some of my Prototypes generate no rf field.

I tested many things, and  finally I found out:

 

When I heat up the PN532 (60-100°C with hot air gun) I see on my scope that suddenly the rf field is there, and all is working well.

I can see this behavour at 4 of 7 curcuit boards, the other 3 are working well.
After cooling down the boards and repowering them, there is no field again.
When I repower them, when they are hot, all is working well.

 

I did the following things without success:

  • Powered the Chip from an other power source
  • Reseted and reinit the PN and the CPU during the power wasn't removed
  • Reading Error Register (no Errors were detected)
  • lower the SPI frequency from 4MHz tto 2,7MHz

 

 

Could it be, that the parts are damaged, because of hand soldering with hot air gun (380°C for 15s)?

Or do you think it's because of some part tolerance?

 

Please tell me your ideas, we want to start our first production series very soon.

 

Thank you,

Regards, Michael

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