Our customer made prototype board using the MK61FN1M0VMJ15.
Previously they will use the 32.768 KHz crystal, but they decide to remove it crystal to reduce BOM cost, because they don't needed the RTC now.
According to the following discussion, NXP recommended EXTAL32 tied to GND.
https://community.nxp.com/docs/DOC-100165
However their board does not have a pattern for EXTAL32 tied to GND.
Here is their questions.
1. What kind of problem occurs if they don't EXTAL32 tied to GND even if they don't use the RTC?
2. Please let us know a reason why they should EXTAL32 tied to GND by remake the board.
Please reply immediately, because it is necessary to decide whether they remake the board by tomorrow..
Best regards,
Takashima
Hi
That document seems haven't be updated for a long time.
The customer can refer the "Table 57. Recommended connection for unused analog interfaces" in K65P169M180SF5V2. This document is newly updated although it is for K65.
Best Regards,
Robin
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