Ideal NFC antenna inductance for PN7642

[KLL]

Is there an ideal inductance for NFC antennas working with the PN7642?  The PN7160 antenna design guide states "Out of experience it turns out to be optimum to have an inductance around L ≈ 1 µH for
a proper matching. But a wide range of L ≈ 300 nH up to L≈ 3 µH can be still matched
properly."  Does this apply to other NFC ICs as well, such as the PN7642?

[danielchen · Accepted solution]

Hi @KLL 

Yes, you are right

Please refer to AN11706:  PN7462 family Antenna design guide, page 13

Out of experience it turns out to be optimum to have an inductance around L ≈ 1μH for a proper matching, but a wide range of L ≈ 300nH up to L≈ 4μH still can be matched properly, so typically 1 up to 4 turns in the normal range of antenna sizes are used.

Regards

Daniel