topic Re: AN12365 - High field strength mode in NFC

AN12365 - High field strength mode

TheQuux — Fri, 18 Jul 2025 15:53:46 GMT

In AN12365, Table 2, there is reference to > 20 mW energy harvesting being possible when in high field strength mode.

I've done this, and am not getting more than 20 mW, and I'm wondering if I need to do something to configure the modulation scheme?

I'm using a NXP5190 (PNEV5190BP eval board) with the reader library to talk to the NTAG5332 on a OM2NTP5332 eval board.

I'm not seeing any information on how the 5190 must be configured in order for this to work. Is there some information that shows how to do this?

Re: AN12365 - High field strength mode

EduardoZamora — Fri, 18 Jul 2025 22:22:54 GMT

Hello @TheQuux

The High Field Strength optimization requires an industrial or specially designed VCD/Reader, while PN5190 is an NFC Reader with relatively low power output.

Regards,
Eduardo.

Re: AN12365 - High field strength mode

TheQuux — Fri, 18 Jul 2025 22:30:19 GMT

Eduardo,

The app note says this:

Energy harvesting optimized for high field strength - if expected VCDs be able to output
more strong field (e.g. specially designed VCDs). The high field strength mode can
drive higher power and also supports a VCD with 10 % modulation index next to the
100 % ASK modulation scheme.

Is the 5190 at least not capable of being configured to this modulation scheme? If you must use a special VCD, is there an example of what that looks like? Perhaps a reference design or something? What sort of field strength must it present in order to enable the higher harvesting amount?

Re: AN12365 - High field strength mode

EduardoZamora — Sat, 19 Jul 2025 01:37:14 GMT

Hi,

This tag that can be powered by an NFC-enabled device at close range and by an ISO/IEC 15693-enabled industrial reader over a longer range.

PN5190 is an NFC Forum compliant device, for this reason, it is designed to achieve a reading distance of up to ~10cm depending i.e. on antenna design. While ISO/IEC 15693 should allow a longer operating distance, our NFC Readers cannot achieve this distance.

As mentioned, an ISO/IEC 15693-enabled, powerful industrial reader would be required for High Field Strength configuration; however, we may not have any product that meet your needs in our portfolio.

Regards,
Eduardo.