Data Sheet

 When using NFC-A tag , please add C_tune1 and C_tune2.
 When using NFC-A tag. You should use a NFC Tag antenna coil that must be
connected differential between NFC1 and NFC2 pins of the device.
 The value of C_tune1 and C_tune2 must be tuned to match the selected NFC antenna.
The two external capacitors should be used to tune the resonance of the antenna circuit
to 13.56 MHz.
The required tuning capacitor value is given by the below equations:
An antenna inductance of Lant = 2 H will give tuning capacitors in the range of 130 pF
on each pin. For good performance, match the total capacitance on NFC1 and NFC2.