https://devzone.nordicsemi.com/f/nordic-q-a/107924/inquiry-about-nrf5340-rf-output-impedance-and-matching-circuitDear Nordic Semiconductor Team, We are currently working on a project that involves integrating the NRF5340 MCU. After reviewing the MCU datasheet and HW design guidelines, we noticed that the RF output is not matched to 50 ohms. We would like to seeken-USTelligent Community 13Sun, 26 May 2024 18:41:59 GMThttps://devzone.nordicsemi.com/thread/485926?ContentTypeID=1Sun, 26 May 2024 18:41:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b74110b5-5e17-4810-b31f-11558c12f84anstohs<p>Hi. Is the impedance value also available for the CLAA package? Thanks.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/466897?ContentTypeID=1Wed, 31 Jan 2024 10:03:27 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1a170ffd-6a6e-436b-a7c4-06ab86ca23c8ketiljo<p>Hi</p> <p>The outout impoedance of the PA is not interessting, it&#39;s the load impedance you want to look at. The nRF5340 is not designed for a 50 ohm load on the antenna pin directly. C1 and L1 in the refrence design handle the impedance transformation and provide additional harmonic filtering:&nbsp;</p> <p><a href="https://infocenter.nordicsemi.com/topic/ps_nrf5340/chapters/ref_circuitry.html#concept_refcircuit_config_1">https://infocenter.nordicsemi.com/topic/ps_nrf5340/chapters/ref_circuitry.html#concept_refcircuit_config_1</a></p> <p><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/1172.pastedimage1706695203391v1.png" alt=" " /></p> <p>Note how C1 is grounded:&nbsp;</p> <p><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/8510.nRF5340-qxaa-matching-network.png" alt=" " /></p> <p>Ther shouldn&#39;t be any need to do simulations here if you follow the reference design. But if you still like to do so, the impedance seen into the mathing network, from the ANT pin should be 70 -j42 ohm</p> <p>Best regards,</p> <p>Ketil Aas-Johansen</p><div style="clear:both;"></div>