topic Re: Optimal clock settings for external resonator in Kinetis Microcontrollers

Optimal clock settings for external resonator

zainali — Fri, 19 Nov 2021 13:34:33 GMT

Hi,

I trying to find the optimal settings for system oscillator. I am using external clock source with 8Mhz resonator. The oscillator configuration in reference manual shows 3 modes,

Can anyone guide what configuration should i choose as 8 Mhz is overlapped. Also is gain linked to the accuracy?

The Microcontroller i am using is MK10DN512 and schematic of oscillator can be seen below.

Thanks

Re: Optimal clock settings for external resonator

bobpaddock — Fri, 19 Nov 2021 15:00:35 GMT

High Gain Mode 2 would be the most reliable.

Gain is more linked to power consumption and start time than accuracy.
Accuracy is determined mostly by the grade of the resonator.

I can't speak to this particular chip, however I've seen reliability problems over the years with using low power (low gain) oscillators. They don't always start reliably across voltages and temperature ranges.

If your resonator has internal caps, disable any built-in caps that the chip may offer.

Re: Optimal clock settings for external resonator

zainali — Fri, 19 Nov 2021 17:05:16 GMT

@bobpaddock thanks for valuable information.

For sake of knowledge, is there any reason to go with high gain mode 2.

Thanks again