Does GPO work when ST25DVxxKC is not powered by Vcc, but only by the RF Field?

[GPira.1]

I want to power the ST25DV tag using a pin of the micro (VCC_EEPROM). In my idea, the micro should power it only when there has been a writing on the TAG's EEPROM. I would like to implement this by monitoring GPO, but I'm not sure if this functionality would work if the TAG is not powered through Vcc.

Can I use the 8 pin version for my application, or should I choose a package with VDCG to implement that? In that case I will connect VDCG to the main VDD line and Vcc to VCC_EEPROM.

[Berenice BENVEGUDA · Accepted solution]

Hello,

First of thanks for your interest in ST25DVxxKC product !

Then, GPO pin is an interrupt pin that can be used to alert the I2C host of external RF events or ST25DVxxKC processes activity as you look for. No need of powering by Vcc pin for that purpose.

It works with power provided by RF field.

Concerning the package version :

 the 8-pin ST25DVxxKC packages offer an open drain GPO output. This GPO pin must be connected to an external pull‑up resistor (> 4.7 kΩ) to operate.

the 10-ball and 12-pin ST25DVxxKC packages offer a CMOS GPO output, which requires to connect VDCG pin to an external power supply.

I hope this answers your questions.

Best Regards,

BB