Skip to main content
JGreve
Associate II
November 21, 2022
Solved

NFC06A1 matching circuit impedance

  • November 21, 2022
  • 1 reply
  • 704 views

Hello :)

Does anyone know what the impedance of the existing antenna matching circuit on the X-NUCLEO-NFC06A1 board is? I can't seem to find that information in any of the datasheets. I need the impedance so that I can design a new custom antenna. 

Br. Jørgen

This topic has been closed for replies.
Best answer by Travis Palmer

Hello Jørgen,

The X-NUCLEO-NFC06A1 features AAT. AAT can change the matching impedance in a certain perimeter dynamically. AN5322 provides additional information about the AAT feature.

By setting the register 26h and 27h the matching can be changed from minimum to maximum.

Reg. 26h= 0x00; 27h = 0x00: (minimum)

0693W00000YAgSXQA1.pngReg. 26h= 0x82; 27h = 0x82: (nominal)

0693W00000YAgScQAL.pngReg. 26h= 0x82; 27h = 0x82: (maximum)

0693W00000YAgSmQAL.pngBy default the nominal matching is applied.

For acting only as a NFC reader AAT can be removed and a fixed matching applied.

BR Travis

1 reply

Travis Palmer
Travis PalmerBest answer
ST Employee
February 14, 2023

Hello Jørgen,

The X-NUCLEO-NFC06A1 features AAT. AAT can change the matching impedance in a certain perimeter dynamically. AN5322 provides additional information about the AAT feature.

By setting the register 26h and 27h the matching can be changed from minimum to maximum.

Reg. 26h= 0x00; 27h = 0x00: (minimum)

0693W00000YAgSXQA1.pngReg. 26h= 0x82; 27h = 0x82: (nominal)

0693W00000YAgScQAL.pngReg. 26h= 0x82; 27h = 0x82: (maximum)

0693W00000YAgSmQAL.pngBy default the nominal matching is applied.

For acting only as a NFC reader AAT can be removed and a fixed matching applied.

BR Travis