ST25R3911B芯片在同样的电路下，两块板子上的表现不一致

[chenyuxiang]

哈喽！ST官方，本人使用ST25R3911B这款芯片做NFC识别方案；

同样的电路，做了5块板子，发现天线识别NFC标签的表现不一致；

1、1号板子可以正常识别NFC标签；

2、2号板子不能正常识别标签，需要调节匹配电路参数，且这两款板子调节的参数不一致；

3、将1号的板子调整为2号的参数，1号板子无法识别，工作不正常；

4、其余的板子也是，调整参数都不一致，才能正常工作。

请问，大佬们，这是什么原因？
都是同样的电路。

[Brian TIDAL]

Hi @chenyuxiang 

welcome to this community. 

English is the official language of the community. English will give to your post more visibility and make it easy to understand for all ST Community members and experts.

Therefore, I would suggest to edit your post and translate it to English.

Proposal:

Title: Inconsistant performances of ST25R3911B

Content:

hello! ST official, I use ST25R3911B chip for NFC identification solution;

I made 5 boards with the same circuit, and found that the performance of the antenna in identifying NFC tags was inconsistent;

1. Board No. 1 can recognize NFC tags normally;

2. Board No. 2 cannot recognize labels normally and needs to adjust the matching circuit parameters, and the parameters adjusted by the two boards are inconsistent;

3. Adjust the parameters of board No. 1 to the parameters of board No. 2. Board No. 1 cannot be recognized and does not work properly;

4. The same applies to the rest of the boards. The adjustment parameters are inconsistent in order to work properly.

Please tell me, gentlemen, what is the reason for this?
It's all the same circuit.

Rgds

BT

 

[Ulysses HERNIOSUS]

Hi,

please check if you are looking into manufacturing spread: slightly different antenna geometries (what kind of antenna are you using?, which inductance?), matching component spread (which accuracy did you use? AFAIK 1% parts are recommended), ... 

Perform measurement to find the difference! I would be surprised if coming from the ST25R3911B.

Regards, Ulysses