https://devzone.nordicsemi.com/f/nordic-q-a/29623/about-some-abbreviationsDSP is Digital signal processing，But I first came into contact with the word，I don&#39;t know what is DSP？ Do you have any relevant documents to explain the words？ The second question, I want to know the difference between QFAA and QFAB Thanksen-USTelligent Community 13Sun, 21 Jan 2018 21:50:34 GMThttps://devzone.nordicsemi.com/thread/117675?ContentTypeID=1Sun, 21 Jan 2018 21:50:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d9d7e955-e54e-4f45-a5de-ff68869a2016J&#248;rgen Holmefjord<p>Hi,</p> <p>QFAA and QFAB describes the packet variant of the chip. You should check the <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52/dita/nrf52/compatibility_matrix/ic_revision_overview.html?cp=2_1_3_0">IC revisions overview compatibility matrix</a> for your chip type. Qx indicates that the chip package is QFN package, while Cx indicates that the chip use WLCSP package. the two last letters, together with the build code, is used to distinguish different revisions and amount of RAM/Flash of the chips.</p> <p>Best regards,</p> <p>Jørgen</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/117674?ContentTypeID=1Sat, 20 Jan 2018 08:36:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:27e37ae0-283c-4d40-82f7-a5ec6510c177kont40<p>You can check the book entitled &quot;The Scientist and Engineer&#39;s Guide to Digital Signal Processing&quot; (<a href="http://www.dspguide.com">http://www.dspguide.com</a> ). That is the best DSP course for beginners...</p><div style="clear:both;"></div>