Hello,
Basically the two extra pins (FD and GND) are meant to be connected to an external circuit e.g. an MCU in order to notify to it a defined event as mentioned in chapter 1.4 of datasheet. If you do not require the FD pin, it would be ok to work with the NTAG 21x family: NTAG213/215/216 | NXP
BR,
Ivan.
The NTAG 21x only have die and MOA8 package version. Die bonding is not suitable for us. The MOA8 package is too large. We choose NTAG213F because it has smaller package. Is I correct? If I am correct, for NTAG213F, can we just connect LA and LB to coil and leave FD and GND pin open. Do we need any external components?
Hello,
You are correct, it is smaller regarding the area but it is thicker compared to the other, so please take this into consideration. FD and GND pins are meant to be connected to an external device, FD pin needs an external pull-up resistor. For the antenna tuning, please refer to the following zip file: https://www.nxp.com/docs/en/application-note/AN11276.zip
BR,
Ivan.