https://devzone.nordicsemi.com/f/nordic-q-a/48741/nrf52832-and-ds3231-rtc---question-about-using-32khz-as-lfxoHi I&#39;m considering a design with this precision RTC I intend to use the 32KHz output on XL1 (and XL2 grounded) as I&#39;ve seen done here, but the DS3231 datasheet says the 32KHz is an open drain that needs a pull-up resistor, so do I need a resistoren-USTelligent Community 13Tue, 18 Jun 2019 23:28:54 GMThttps://devzone.nordicsemi.com/thread/193512?ContentTypeID=1Tue, 18 Jun 2019 23:28:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a809f006-ebe8-4446-8d3f-19e082794d6fpolynomialtime<p>Ok that&#39;s what I was leaning towards but thanks for confirming since as you say documentation on this is pretty lacking</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/193511?ContentTypeID=1Tue, 18 Jun 2019 23:24:27 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b9eb9270-5908-41f8-971b-a2da30d34cdcRK<p>Don&#39;t see how it&#39;s going to work if you don&#39;t install one. Although the description of XL1/XL2 used with an external signal is a bit lacking in detail (eg what a &#39;low&#39; signal means and what the input impedence is) just connecting an open drain to an input buffer is going to result in nothing more than a bit of noise around 0V, if even that. You&#39;re going to need a pullup to actually get the voltage to swing.&nbsp;</p> <p>Apart from that, if you&#39;re doing the design, just design for a pullup resistor, if you find (unlikely) that you don&#39;t need one, just leave it N.C.</p><div style="clear:both;"></div>