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Is there any Dc offset on nRF52840 RF port ?

Artak

Is there any Dc offset on nRF52840 RF port? Is it necessary to add a DC blocking capacitor if the load has DC path to ground?

In particular Is it OK to connect a 50 Ohm termination resistor after the LC impedance matching network recommended in datasheet ?

If there is a DC offset dc current will flow through the resistor and the internal circuit bias point will be shifted.

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    Hi Artak! Sorry for the delayed response. Talked to a colleague here at Nordic and he said that there is no DC offset on the nrf52840 port. You therefore don't need a DC blocking capacitor or a termination resistor either. Just attach the port directly to the antenna or whatever you plan to use the RF port for. There is an internal balun that ensures a DC short to ground. There are also some customers that use DC-shorted antennas or front-end modules that wouldn't work with a DC-offset on the antenna output. Hope that answers your question.

    Kind Regards,

    Bjørn

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  • 0

    Hi Artak! Sorry for the delayed response. Talked to a colleague here at Nordic and he said that there is no DC offset on the nrf52840 port. You therefore don't need a DC blocking capacitor or a termination resistor either. Just attach the port directly to the antenna or whatever you plan to use the RF port for. There is an internal balun that ensures a DC short to ground. There are also some customers that use DC-shorted antennas or front-end modules that wouldn't work with a DC-offset on the antenna output. Hope that answers your question.

    Kind Regards,

    Bjørn

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