cancel
Showing results for 
Search instead for 
Did you mean: 

Is ST25R3911B compatible with AMS AS3955 dynamic tag?

PPill
Associate II

Hello,

I am working on a project based on NFC energy harvesting application. I am using AMS AS3955 dynamic tag which offers this functionality with ST25R3911B as the reader. In the ST25R3911B datasheet, it says that NFC type 4 tags are preferred and nothing is mentioned about other tag types.

Can ST25R3911B work with T2T commands(read/write)? If no then please suggest an alternative.​

PS: AS3955 can also work on ISO14443A​ standard, but its mode must be changed to tunneling.

Thank you in advance!​

1 ACCEPTED SOLUTION

Accepted Solutions
Ulysses HERNIOSUS
ST Employee

Hi,

from ST25R3911B chip perspective you can use AM or OOK(bit tr_am is an independent bit). However when using AM for ISO14443A you may/will fail standard compliance (wave shapes). Some/many tags may understand some strong AM modulation as well.

Regards, Ulysses

View solution in original post

4 REPLIES 4
Ulysses HERNIOSUS
ST Employee

Hi,

the AS3955 always works in iso14443a standard. Depending on the selected mode it can emulate an NFC type 2 (Level 3 by HW) or NFC type 4 (Level 4 by MCU software) tag.

ST25R3911B supports of course all ISO14443A protocol. Not sure where you find a mention of type 4 in its datasheet. If you happen to look at the ST25R3911B-DISCO software you will find some direct support in the mifare_ul.* files.

Regards, Ulysses

PPill
Associate II

@Ulysses HERNIOSUS_O 

Thank you sir for the clarification.

I just want to confirm one more thing please, so by working on ISO 14443A standard I can only go for OOK Modulation, isn't it? Or can I use AM modulation as well for the communication?

Sorry for the inconvenience. Thanks in advance for all the help.:smiling_face_with_smiling_eyes:​

Ulysses HERNIOSUS
ST Employee

Hi,

from ST25R3911B chip perspective you can use AM or OOK(bit tr_am is an independent bit). However when using AM for ISO14443A you may/will fail standard compliance (wave shapes). Some/many tags may understand some strong AM modulation as well.

Regards, Ulysses

PPill
Associate II

@Ulysses HERNIOSUS_O​ 

I want to maintain a constant field for energy harvesting. I think I got your point.​

Thank you for the help.:smiling_face_with_smiling_eyes: