PN7462AU: Contact card issue: No ATR

[jeanlucchaillat]

Hi everybody,

I have strange issue with a custom design reader based on the PN7462AU and on the example phExCcid.
The hardware is 100% following the documentation and the NXP reference design.
In a small production of 10 readers, all programmed with the same software and the same EEprom data, only 4 are working as expected and 6 have the same issue:

• When a contact card is inserted no ATR is read by the phhalCt_AtrParser() function, I get a time out error after 10s.
• The function phhalCt_WaitForAtrBytes() returns a timeout error after 10s of card insertion.
• I checked the I/O pin of the smartcard with a scope and I saw the ATR is properly sent by the card at the right time during the activation sequence.

The strange thing is if I insert a mute card the function phhalCt_WaitForAtrBytes() returns MUTE_ERROR as soon the card is inserted (no 10s timeout).

It means the 7816 UART is able to differenciate a card emitting an ATR and a mute card, with the faulty readers nothing is stored in the 7816 FIFO!

With the LPC Link-2 and MCUxpresso I ran the phExCcid example in debug mode and with the 6 faulty readers there is no call to CTIF_IRQHandler() while the card sends its ATR.

These 6 readers behave like if the 7816 UART was not enable?

All the soldering had been checked 4 times, all the voltages on VBUSP, VBUS, VUP are Ok.
During the card activation the Card VCC, RST, CLK are all OK. Decoupling capacitor are closed as possible to the PN7462.

Any idea on how to solve this issue.

Jean-Luc.

[IvanRuiz]

Hello,

This is not a known issue and seems a hardware problem. Please check your design or environment since we cannot recreate it with the eval board.

Thank you for your comprehension.

BR,

Ivan.

[jeanlucchaillat]

Hello,

Thank you for your answer. My colleagues and I are going to recheck the hardware.

Best regards,

Jean-Luc Chaillat

De : IvanRuiz

Envoyé : lundi 20 avril 2020 20:50

À : Jean-Luc Chaillat <jl.chaillat@cartadis.com>

Objet : Re: - Re: PN7462AU: Contact card issue: No ATR

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Re: PN7462AU: Contact card issue: No ATR

reply from IvanRuiz<https://community.nxp.com/people/IvanRuiz?et=watches.email.thread> in NXP Designs - View the full discussion<https://community.nxp.com/message/1300752?commentID=1300752&et=watches.email.thread#comment-1300752>

[jeanlucchaillat]

Hello to all involved with hardware issues.

We identified the issue why 6 out of 10 custom contact card readers using the PN7462 were not working properly.

We put these 6 boards in a freezer (-18°C) for 5 minutes and retested them quickly.

All these 6 boards were working OK, the card ATR was properly stored in the FIFO and CTIF_IRQ was generated properly. Once these 6 boards were recovering the ambiant temperature they all stoped to work.

We came to the conclusion, the internal connection of the UART 7816 to the I/O card pin is broken at ambiant temperature. We suppose this junction is more fragil than the others and have been destroyed during the soldering process of the PN7462 on the PCB.

We now must check with our soldering subcontractor if the temperature of 260°C was not exceded and for long.

Is there someone who experienced the same type of problem with HVQFN packaging?

Best regards,

Jean-Luc.

[vicentegomez]

Hi

No, we have not reported by other customers a problem with this device.

If you got the solder profile and can share it, I will be glad to review it.

Also, ask your manufactures if they use manual solder using a "hot air gun" to perform any rework, maybe here is the problem.

Please check that there is not any ceramic capacitor damaged.

Just for a test can you put a let's say damage device on a good board and a good device on a damaged board. This in order to check if the problem is the PN7462 or the hardware 

Regards