My experience of MFRC522 on how to get more RF power

Discussion in 'General Electronics Chat' started by Maydori, Jul 18, 2016.

  1. Maydori

    Thread Starter New Member

    Jul 18, 2016
    I want to share my experience that how to get more rf power from china made rc522 board.
    My project uses MFRC522 board and Mifare Ultralight C cards.
    This board can't produce enough RF energy to get Ultralight C card up and running
    MFRC522 datasheet says that max TX current is 150mA, but measured current was only 7mA.
    I have a very good RF design experience so I started to measure whole RF part and make full tuning.
    And what I found, antenna is tuned, not perfectly but usable, so was matching cirquit. But used 2.2uH
    inductors does not meet with required parameters.
    Solution: Replace inductors L1 and L2 with same inductance (2.2uH) but higher operating current.
    Now RC522 can read Ultralight C cards with no problem, also NTAG203 card reading distance is ~70mm

    RC522 RF output pins are very static sensitive!
    Without proper equipment you can easly
    damage your rc522 reader board!!
    Hope my experience could help you.But if there was something wrong,you can point it out.