Matching antenna and EVB for ST25R3914-AQFT

[RAlbi.1]

Hi guys,

I must to replace the old obsolete chip ST25R3910-BQFT.

I Finded the similar chip ST25R3914-AQFT, it change little abuot pinout and software but my first problem is the antenna matching for 13.56 MHz RFID application. Is possible to do the same matching that i used for ST25R3910-BQFT?

I downloaded the ST25R Antenna matching tool software, but I not finded the type ST25R3914

I don't find the avaluation board for ST25R3914-AQFT, so is not possible for me to test the device and the put the ST25R3914-AQFT for new possible project.

please help me because I' dont' know what to I do.

thanks 

Ciao, Roberto

[Ulysses HERNIOSUS]

Hi Roberto,

ST25R3914 is essentially the automotive variant of ST25R3911B. Additional chips in this family of chips are ST25R3912 and ST25R3915 (except for removed features of course). Everything which you find for ST25R3911B will also hold for ST25R3914.

If I recall correctly then the same matching as on ST25R3910 should be usable but I will check back with my colleagues.

BR, Ulysses

[RAlbi.1]

Hi Ulysses,

thanks for your answer! I'll wait you check.

I think that I will use the ST25R3914 because the automotive variant guarantees me greater longevity of the component.

best regards Roberto

[Travis Palmer · Accepted solution]

Hello Roberto,

every application note valid for the ST25R3911B is also valid for the ST25R3914/15.

You should have a look at chapter 7 of AN4974 and execute measurements which are applicable for you.

https://www.st.com/resource/en/application_note/an4974-antenna-matching-for-st25r3911bst25r391x-devices-stmicroelectronics.pdf

You should also check the capacitive voltage divider to be setup around 2.5V to 2.7V - this should also be mentioned in this application note in chapter 3.4.

It can be either measured via an DSO and GND-springs or by using the direct command measure amplitude.

Please let us know, if you have additional questions.

BR Travis

[RAlbi.1]

Hi Travis

for now thanks, if i need to other information I will write you

thanks