https://devzone.nordicsemi.com/f/nordic-q-a/5037/capacitors-for-16mhz-xtalWhat capacitors would you recomend for this 16MHz Quartz http://www.jauch.de/ablage/med_00000848_1411137106_JXS32-180914.pdf to ensure 40ppm frequency tolerance for nrf51822? Is it correct to use 12pF?en-USTelligent Community 13Fri, 16 Jan 2015 07:07:32 GMThttps://devzone.nordicsemi.com/thread/17758?ContentTypeID=1Fri, 16 Jan 2015 07:07:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b2250a85-c74b-44c8-af91-cd55086c432fDeimantas<p>Thanks. ;)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/17757?ContentTypeID=1Thu, 15 Jan 2015 10:43:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fea33eb2-6329-48cb-be83-b1ee7658f05bFormerMember<p>The formula for finding the values of the capacitors C1 and C2 to be used with a crystal is:</p> <p>C1 = C2 = 2*C_l - C_pcb - C_pin,</p> <p>where</p> <p>C_l: Load capacitance of the crystal</p> <p>C_pcb + C_pin is approximately 4 pF.</p> <p>The above formula can be found in the whitepaper &quot; <a href="https://www.nordicsemi.com/eng/nordic/download_resource/20346/6/1331056">Crystal Oscillator Design Considerations</a>&quot; and chapter 3.6.1 in the nRF51822 Product Specification.</p> <p>The maximum value of C_l depends on the crystal, see the nRF51822 Product Specification, chapter 8.1.2.</p> <p>In your case, the standard value for C_l is 12 pF, it means that C1 = C2 = 20 pF.</p><div style="clear:both;"></div>