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Explorer II
July 14, 2022
Solved

About ST25R3916 typical schematic and BOM

  • July 14, 2022
  • 4 replies
  • 1489 views

We are developing RFID reader with ST25R3916. As design reference and parts selection, I wonder if we can get the schematic and BOM of ST25R3916-EMVCO.

best regards

Dai Sai

    This topic has been closed for replies.
    Best answer by Peter BENSCH

    You will find additional hints regarding AAT (Automatic Antenna Tuning) in the data sheet of the reader chip ST25R3916.

    AAT_series and AAT_parallel are controlled by two control signals AAT_A and AAT_B from the ST25R3916 and each change voltage-controlled variable capacitors (varicaps) LXRW0YV600-054. These varicaps have a control input at pin 2 whose voltage sets the capacitance of the capacitor between pin 3 and pin 4.

    The Automatic Antenna Tuning now works in such a way that the signal

    • AAT_series (AAT_A) changes the series capacitance and
    • AAT_parallel (AAT_B) the parallel capacitance of the NFC resonant circuit,

    which allows the resonant frequency of the resonant circuit to be adjusted and optimized.

    Does it answer your question?

    Regards

    /Peter

    4 replies

    DSai.1Author
    Explorer II
    July 15, 2022

    Dear Sir,

    I found a datasheet about X-NUCLEO-NFC06A1, there is a schematic diagrams about the HW. I think it may be a good reference for my design. But in the diagrams on Page 3, I can not understand AAT series and AAT parallel. Could you give me any hits about them?​

    Technical Moderator
    July 15, 2022

    You will find additional hints regarding AAT (Automatic Antenna Tuning) in the data sheet of the reader chip ST25R3916.

    AAT_series and AAT_parallel are controlled by two control signals AAT_A and AAT_B from the ST25R3916 and each change voltage-controlled variable capacitors (varicaps) LXRW0YV600-054. These varicaps have a control input at pin 2 whose voltage sets the capacitance of the capacitor between pin 3 and pin 4.

    The Automatic Antenna Tuning now works in such a way that the signal

    • AAT_series (AAT_A) changes the series capacitance and
    • AAT_parallel (AAT_B) the parallel capacitance of the NFC resonant circuit,

    which allows the resonant frequency of the resonant circuit to be adjusted and optimized.

    Does it answer your question?

    Regards

    /Peter

    DSai.1Author
    Explorer II
    July 15, 2022

    Dear Peter,

    thank you very much for your advice. I do understand what you said.

    best regards

    Dai

    Technical Moderator
    July 15, 2022

    Great!

    If the problem is resolved, please mark this topic as answered by selecting Select as best. This will help other users find that answer faster.

    Good luck!

    /Peter