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Visitor II
August 12, 2026
Question

How to add an external power amplifier (PA) to the RF output of an ST25Rx00 reader

  • August 12, 2026
  • 2 replies
  • 85 views

I am currently working with an ST25R300 reader IC and would like to increase the available RF power at the antenna in order to achieve a higher field strength/read range.

I only need ISO/IEC 15693 modulation.

I need about 5-8 watts of output power.

Is it possible to drive a H bridge driver IC with the push pull output of the ST25R300? And what about deadtime etc.

Are there any reference designs or application notes from ST showing an ST25R device combined with an external PA?

 

Thank you in advance!

2 replies

Associate
August 12, 2026

This is also the issue I am hoping to resolve.

Marcel Rossignol
ST Employee
September 2, 2026

Hello Redia,

unfortunately, we do not have a reference design or application note for an external PA.

We did some investigations in the past with Class E & H-bridge amps.

It is possible to drive an H-bridge with the reader push-pull output, but it leads to a lot of challenges (high costs, EMI, NFC Forum compliance, heat & efficiency).

Best regards,

Marcel