https://devzone.nordicsemi.com/f/nordic-q-a/26505/chip-ceramic-antenna-plus-external-crystalI am planning to use MDBT42Q with Chip/Ceramic antenna. I can see in the data sheet they have mentioned an optional 32.768khz crystal. see page 32 (8. Reference Circuit): statics3.seeedstudio.com/.../MDBT42Q-Version_B.pdf Now in order toen-USTelligent Community 13Thu, 02 Nov 2017 00:16:13 GMThttps://devzone.nordicsemi.com/thread/104291?ContentTypeID=1Thu, 02 Nov 2017 00:16:13 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1f94e50d-0971-48a5-b34e-c94bd14c11f6RK<p>No. There are at max only two crystals and the crystal has nothing at all to do with the antenna.</p> <p>The MDBT42Q has one HF crystal on it (required). It doesn&#39;t have the optional 32kHz crystal on the board, if you want to use an external crystal, you have to supply it. There is no 32kHz crystal &#39;in the nrf52 chip&#39;. The chip has an internal RC oscillator.</p><div style="clear:both;"></div>