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Associate
April 16, 2024
Solved

ST25R3916B - Resistive Divider RF input

  • April 16, 2024
  • 1 reply
  • 1008 views

Hi,

 

is it possible to use the ST25R3916B with an resisitve divider (instead of the capacitive divider) at the RF Inputs to limit the input voltage to a safe value.

In case this is possible, is an additional DC-Block needed?

I am driving a purely resistive load with the RF Outputs.

 

Thank you very much. 

Moritz

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

Hi,

 

The chip is biasing the input signal (sinus) coming from the antenna using AGD voltage.

It means that the sinus is DC biased by ~1.5V. Therefore the Antenna needs to be DC de-coupled from the antenna.

All the internal filters are designed in a way to operate with this proposed capacitiv voltage divider.

A resisitve voltage divider is not recommended and operation is not guaranteed.  

BR Travis

1 reply

Travis Palmer
Travis PalmerBest answer
ST Employee
June 12, 2024

Hi,

 

The chip is biasing the input signal (sinus) coming from the antenna using AGD voltage.

It means that the sinus is DC biased by ~1.5V. Therefore the Antenna needs to be DC de-coupled from the antenna.

All the internal filters are designed in a way to operate with this proposed capacitiv voltage divider.

A resisitve voltage divider is not recommended and operation is not guaranteed.  

BR Travis

Moritz_Author
Associate
June 12, 2024

Hi Travis,

thank you very much.

Kind regards

 

Moritz