reducing the two 32768 crystals to one in 8MPLUSLPD4-CPU

[diegoperez]

Hi,

In the 8MPLUSLPD4-CPU there are two 32.768KHz crystals, one for imx8mp and other for PMIC. In order to reduce components:

1. Is it suitable use only one 32.768 crystal on PMIC side and connect CLK_32CLK_OUT from PMIC to RTC_XTALI of imx8mp?
2. PMIC PCA9450CHN can work without external 32.768KHz crystal?

Thanks, and best regards.

Diego.

[nxf63675 · Accepted solution]

Hi Diego,

1. Yes, it is but be aware of the recommendation that comes on the hardware developers guide Table 11. Oscillator/Crystal recommendations for the correct function of the processor.

2. Yes, the PMIC can work without problems if you do not want to use it, do not leave floating the XTAL_IN terminal tie this to GND, and the XTAL_OUT terminal you can leave floating.

Hope this helps you.

Regards,

Israel.

[diegoperez]

Thanks @nxf63675 for your reply.

Which of the two solutions (one cristal in the PMIC or one cristal in the imx8mp) is more advisable to use only one crystal?

BR

Diego.

[nxf63675]

Hi Diego,

Well, that is up to you but the PMIC works perfectly without the crystal and the crystal that you need on the processor is a must and has to be according to the specification.

Hope this helps you to decide.

Regards,

Israel.