https://devzone.nordicsemi.com/f/nordic-q-a/56051/thingy-91-qm14501-enable-circuitHi There, The attached image shows the part of the schematic responsible for the enabling of the QM14501. I was wondering if there was a particular reason that the mosfet is controlled by an AND gate rather than using GPIO from the nRF9160 to controlen-USTelligent Community 13Thu, 02 Jan 2020 13:06:57 GMThttps://devzone.nordicsemi.com/thread/227236?ContentTypeID=1Thu, 02 Jan 2020 13:06:57 GMT137ad170-7792-4731-bb38-c0d22fbe4515:af88e0e0-b2e9-466f-9f22-5014400abf34&#216;yvind<p>Hello,&nbsp;</p> [quote user=""]I was wondering if there was a particular reason that the mosfet is controlled by an AND gate rather than using&nbsp;GPIO from the nRF9160 to control it? Any information would be appreciated[/quote] <p>Yes, the reason is due to the antenna tuning. As the Thingy:91 is designed to work worldwide, it is capable of using different bands. The GPS signal is provided through QM12038, see image below form <a href="https://www.nordicsemi.com/Software-and-tools/Prototyping-platforms/Nordic-Thingy-91/Download#infotabs">Thingy:91 Hardware Files</a><br /><img alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/600x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-800b42e3a42b4d668b5b6ca22cc5d844/pastedimage1577970089273v1.png" /></p> <p>When RF_SW1, RF_SW2, and&nbsp;<span>RF_SW3 are all set to one, the GPS band is enabled. The same signals are therefore used to indicate that the LNA can be enabled using the AND gate.</span></p> <p><span>More information can be found in <a href="https://infocenter.nordicsemi.com/topic/ug_thingy91/UG/thingy91/intro/frontpage.html">our inforcenter</a>.</span></p> <p><span>Kind regards,<br />Øyvind</span></p><div style="clear:both;"></div>