"How to make the NFC tag invalid after power loss?"

[ljack.2]

I am writing this letter to seek your advice regarding a problem we are currently facing. We have an application scenario that involves a device with a battery, and we want the NFC tag on the device to become invalid when the battery runs out, thereby preventing the card reader from reading the contents on the tag.I have tried to use passive tags and attempted to disconnect the induction coil through a special circuit, but the effect was not satisfactory. I was wondering if you know of any good solutions for this.

Thank you very much for your help, and I look forward to your reply.

Sincerely

[Ulysses HERNIOSUS · Accepted solution]

Hi,

there are dynamic tags like the ST25DV series where you can check indirectly the battery state by trying to access the mailbox which needs to be served by a powered MCU on tag side.

Also some tags support something like a tamper detect pin, I assume you can also design here some solution to use it to detect battery level (using battery to close/open it).

Best Regards, Ulysses