What is the maximum power transmitted through NFC that can be harvested?

[havnil]

What is the maximum power an NFC-enabled card can draw from a contactless payment terminal? What are the determinants (i.e. card reader voltage)?

What techniques are available for harvesting this current?

Background: Trying to figure out what the power threshold is for say a biometric sensor on a payment card is.

Thanks!

[havnil]

Hi, 

Thank you for your answer. Doesn't the result depend on the receiving antenna? 

It would be very helpful if someone had done the measurement job from a standard ISO14443-2. 

[slavekprzepiors]

Hi,

The field transmitted is a given.

How do you want to harvest the field it is up to you.

And, of course it is receiving antenna dependent as well as load attached to it.

There are equations that tells you what parameter of the antenna are influence the energy harvested.

Just look into some applications from NXP or more general from physics books.

The ISO10373-6 show how to measure the field.

[slavekprzepiors]

Hi Haavard,

The question like this can be answered based on the ISO14443-2 standard maxim magnetic field transmitted - 7.5A/m

within operating volumes. Besides - minimum field is 1.5A/m.

You can calculate/build/measure what will be the power in the receiving part of the circuit at specific distance.

Regards,

Slavek