I plan to do a PCB with an MCU and it will include one NCF reader IC + PCB antenna in the same board. I have pre-selected one of the following ICs:


Both ICs support ISO-14443 and ISO-15693. According to Wikipedia, ISO-15693 specify a maximum read distance of 1 to 1.5 meters.

My application is an electronic lock for doors and, for security reasons, I would like my NFC reader IC could read the tags only within a little distance range, at around 15 centimeters (~6 inches) of maximum distance. Is this possible?

My board is to be an active NFC reader that will read and external passive tag.

Or will I need another solution for NFC reader IC to reach such maximum distance?

EDIT: I want the reader IC to be able to read/write external tags, and also with the smartphone via NFC.

  • 1
    \$\begingroup\$ Wouldn't it be better to use MFRC522 and any MCU? Its used exactly for what you need. nxp.com/docs/en/data-sheet/MFRC522.pdf Video tutorial: youtube.com/watch?v=KQiVLEhzzV0 \$\endgroup\$ May 11, 2020 at 18:00
  • \$\begingroup\$ @CFCBazarcom The datasheet of this IC shows it is "ISO/IEC 14443 A/MIFARE compatible", so it is NFC compatible, correct? \$\endgroup\$
    – abomin3v3l
    May 11, 2020 at 18:12
  • \$\begingroup\$ --> Typical operating distance in Read/Write mode up to 50 mm depending on the antenna size and tuning \$\endgroup\$
    – abomin3v3l
    May 11, 2020 at 18:19
  • 1
    \$\begingroup\$ When you say near field communication compatible, it can be a lot of things. Which standard do you need. This is exactly and NFC device, its used for doors and such. It works on a short range. It has an NFC antenna, which can read a card, but the compatibility is ISO/IEC 14443 A/MIFARE type of cards. Also it supports NTAG. \$\endgroup\$ May 11, 2020 at 18:19
  • \$\begingroup\$ I want the reader of the board to be able to read external tags, and also to communicate with smartphone via NFC. \$\endgroup\$
    – abomin3v3l
    May 11, 2020 at 18:21

1 Answer 1


For a door device, the MFRC522(or RC522) are good enough. They have an SPI or UART interface and are used commonly in these devices. However they do not support a smartphone tag.

For reading a smartphone tag, you need a better chip which supports the smartphone NFC standard, like PN532. It works in almost the same way, but supports more types of cards, including phones.

  • \$\begingroup\$ My question is about the distance of around 15cm. \$\endgroup\$
    – abomin3v3l
    May 11, 2020 at 18:33
  • 1
    \$\begingroup\$ Can you give us your list. Reducing the distance is not really a good decision. \$\endgroup\$ May 11, 2020 at 18:35
  • \$\begingroup\$ I would use one of the part numbers of the original post, or ST25R3911B. Supposing it works at 25cm in practice, is there any way to try to reduce to 15cm? like with a detune of the RF circuit? \$\endgroup\$
    – abomin3v3l
    May 11, 2020 at 18:51

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