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NFC Voltage level

Shalom Gerbi

Hi Team 
We are working on NFC for our new product.
When we measure the power level each GPIO we don't reach more than 700mv.
Changing the antenna to a larger antenna did not increase the power level
My question is why we don't see any change in the power level if we change the antenna to a bigger antenna

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  • 0 in reply to Shalom Gerbi

    I don't understand why you are measuring, and refereeing to Vsense.. Vsense is defining the threshold level for the NFC1 and NFC2 pins, differential voltage, for when it's in Sense mode:
    "Wake-on-field is supported in SENSE mode while the device is either in System OFF or System ON mode. When the antenna enters an NFC field, an event will be triggered notifying the system to activate the NFC functionality for incoming frames. In System ON, if the energy detected at the antenna increases beyond a threshold value, the module will generate a FIELDDETECTED event."




    For tuning:




    Best regards,
    Kaja

  • 0 in reply to Shalom Gerbi

    Again you don't answer my question, Iam measuring the signal, because I want to get a good quality NFC signal for the strength of the link.

    I adjust the antenna and the capacitance.
    Increasing the inductance of the antenna should give me a higher voltage according to the transformer.
    I do not see that .that why I am asking , the NFL should works behind a enclosure and I need to get a good signal 

    Now please advise how I can increase the voltage level

  • 0 in reply to Shalom Gerbi

    Hi,

    so Vs, in your picture and Vsense is not the same thing..


    Measuring Vs, is not possible in the way you are trying to do, as our IC will change the voltage over NFC1 and NFC2, so when you change the load/antenna, the voltage will still stay the same.. 

    To make NFC stable, make sure the antenna our IC is tuned, and that the field is strong enough and it's easier to get good NFC connection of the antenna's are the same. 

    Best regards,
    Kaja

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