3-slot IC card carrier board with field indication function

This IC card carrier board is only suitable for use with 13.56MHz XOA2 package chips.

The antenna coil is generated using ST's design tool, the inductance value is 2.89uH, and the matching load capacitance is about 47.6pF.

Tool link: Calculate PCB coil inductance (ST account required)

In order to adapt to the different load capacitance values ​​of different IC card chips, the position of the resonance compensation capacitor of TBD is reserved, which can be adjusted according to the communication situation of the IC card chip used. The longest communication distance is used as the appropriate mark for adjustment. The UID card chip I use needs a resonance compensation capacitor of about 10pF.

The onboard LED light can indicate the strength of the RFID field, but in order to avoid interfering with the card's wireless communication during operation, please do not use a current-limiting resistor below 330 ohms. Theoretically, the larger the current limit resistor, the less likely it is to interfere with communication, but the corresponding brightness will also decrease.

There are two PCBs, one is the carrier board with components, and the other is the frame. When assembling, the order from bottom to top is: carrier board-frame*4-2mm acrylic board, and the screws are M3*12 flat-head screws.