Custom board USB - PN7462

[benten]

Hi All,

We develop custom board with PN7462 with USB support.  We created the same two PCBs. And we wrote to flash phExCcid app.

One of them works. One of them has a problem with connection USB because OS said "Unknown USB Device (Device Descriptor Request Failed)". We see that hwUSB_Init retuns LPC_OK. And we see that HIF_IRQHandler is called.

We excluded that is soldering responsible.

Do you have any ideas what we should do/check?

Thanks,

Kamil

[IvanRuiz · Accepted solution]

Hello,

This sounds like a hardware problem of the design if one board works and the other does not. Please check voltage levels on VDD and TVDD to make sure that the board is properly powered and check that correct components are on their place.

It will be helpful to refer to PN7462 eval board design files:

Layout: https://www.nxp.com/downloads/en/schematics/DF4823.PDF 

Schematics: https://www.nxp.com/downloads/en/schematics/DF4824.PDF 

Regards,

Ivan.

[benten]

We changed IC -> its helps. Thank you.