TRF7970A: using two devices as RF link

Shai Berman

Part Number: TRF7970A

Hello team,

I have a customer who wants to know if it possible to use two TRF7970A in order to perform simple communication with each other (like a linker based 13.56Mhz).

And whether it is possible to reach a distance of 30 cm (with both of the sides are active)?

Thanks,

Shai

over 7 years ago

0 Ralph Jacobi over 7 years ago

TI__Guru*** 135355 points

Hello Shai,

Shai Berman said:
I have a customer who wants to know if it possible to use two TRF7970A in order to perform simple communication with each other (like a linker based 13.56Mhz).

Yes, that is known as Peer-to-Peer communication and we have a whole app note+software stack for it: http://www.ti.com/lit/pdf/sloa192

Shai Berman said:
And whether it is possible to reach a distance of 30 cm (with both of the sides are active)?

No, that is not possible, P2P doesn't get that sort of range. 5cm is typical, 10cm is very good.

Also the mode they are loosely referencing is what is called Active P2P mode and it is unreliable compared to the typical Passive P2P mode. The TRF7970A and our NFC stack can support both modes, but we always recommend Passive P2P which is better defined and provides more robust communication.

0 Shai Berman over 7 years ago in reply to Ralph Jacobi

Mastermind 7405 points

Ralph,

Thank you for your inputs regards, the P2P approach.
I have read several E2E threads about range (for ex. e2e.ti.com/.../546390
There was mentioned in order to achieve higher distance there is a need to add an external amplifier and using multiple antennas.
Can you please elaborate about it, the customer has a plenty of space and power for his application. Thanks.

BR,
Shai

0 Ralph Jacobi over 7 years ago in reply to Shai Berman

TI__Guru*** 135355 points

Hello Shai,

That discussion and others on E2E about power amplifiers were for reader/tag systems. Not Peer-to-Peer systems. We have never experimented with any power amplifiers for Peer-to-Peer systems and cannot comment on the viability of such a setup.

Furthermore, we no longer offer any support for any power amplifier applications.

The customer can investigate extending P2P range with a power amplifier if they desire, but we will not support such an application.

0 Shai Berman over 7 years ago in reply to Ralph Jacobi

Mastermind 7405 points

Ralph, Thank you very much.

BR
Shai

0 Shai Berman over 7 years ago in reply to Ralph Jacobi

Mastermind 7405 points

Ralph,

Maybe you can point out a few good resources that my customer can start leaning the case, Thanks a lot and regards.

Shai

0 Ralph Jacobi over 7 years ago in reply to Shai Berman

TI__Guru*** 135355 points

Hello Shai,

I think Josh has posted a power amp design or two on the forum, you could try searching to find those perhaps. We don't have any official documentation to share for that.

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TRF7970A: using two devices as RF link