https://devzone.nordicsemi.com/f/nordic-q-a/124741/rtc-crystal-calculationHi, We are in the process of changing the 32.768 kHz RTC crystal in an existing product and require additional data to verify the electrical properties of the crystal. For the oscillator calculations, I need the following parameters: Minimumen-USTelligent Community 13Thu, 02 Oct 2025 08:54:04 GMThttps://devzone.nordicsemi.com/thread/550441?ContentTypeID=1Thu, 02 Oct 2025 08:54:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:dca90c13-dcb0-436b-a7b9-d06809eb3c10Kim_JE<p>Hi Kenneth,</p> <p></p> <p>Thank you for your reply.</p> <p data-start="126" data-end="513">For our other products, we rely on detailed calculations to ensure that the circuits function as intended, and I believe the same approach would be beneficial for the RTC oscillator. However, since this information is not readily available, I will follow your recommendation and proceed by reviewing the specification you provided and comparing it with the crystal I consider suitable.</p> <p data-start="515" data-end="553">Thank you again for your assistance.</p> <p>Best regards.</p> <p>Kim</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/550423?ContentTypeID=1Thu, 02 Oct 2025 07:38:11 GMT137ad170-7792-4731-bb38-c0d22fbe4515:01d4a646-3295-4062-a21c-f5a4071aa460Kenneth<p>Hello,</p> <p>There is no need for you to know these details, as we have specific in the datasheet the specification of the external crystal oscillator must meet to work reliably with the nRF52840. The parameters for the 32kHz crystal is listed here:<br /><a href="https://docs.nordicsemi.com/bundle/ps_nrf52840/page/clock.html#ariaid-title39">https://docs.nordicsemi.com/bundle/ps_nrf52840/page/clock.html#ariaid-title39</a>&nbsp;</p> <p>So make sure to choose a crystal part number that meet those criteria.</p> <p>Kenneth</p><div style="clear:both;"></div>