DLP-7970ABP: TRF7970A NFC Reader Antenna Multiplexing

Hello Josh,

It looks like, there are few differences in the matching/tuning  circuit between the TRF7960a document and DLP-7970ABP schematic. (Circuit connecting  TX_OUT, RX_IN1, RX_IN2 pins).

I found the DLP 7970ABP schematic from www.ti.com/lit/pdf/tidr502.

Is the antenna board (Matching circuit and Antenna) also identical in both the examples? And the antenna dimensions same as DLP-7970ABP?

It would be good reference, if I can get the source file.

Thank you.

Sincerely,

Manoj

Hello Manoj,

The antenna dimensions were not the same between the two schematics, therefore the matching circuit will be different.

As far as a good reference, you should leverage our antenna tuning guide for your own hardware: http://www.ti.com/lit/pdf/sloa241

When it comes to antenna matching there is little value in comparing tuning circuit values for various boards, the important part is understanding how those values were chosen and that is what SLOA241 details.

Hello,

I have made a PCB layout of Antenna and the matching circuit using the help of the reference design of the TRf7970a based ez430-TRF7970a. (www.ti.com/.../TIDM-NFC-EZ430-MODULE).

Here is my schematic and layout.

Schematic and layout.pdf

I want to know, how i could calculate the theoritical inductance of the antenna before giving it to fabrication. Is there anything I could add in the layout?

Sincerely,

Manoj