Crystals and oscillator parts used in FRDM-K22F board

[vishalgirisagar]

Hi All,

  I am using K22F board. I have tested a prototype of my software on this board. And it works completely. Now I am in next stage of building my own board using the same MCU. I am stuck with oscillators and crystals used. I want to used both RTC crystal (32.768KHz) and 8Mhz crystal. From the schematics, I see the following.

  I have no clue how to use the crystals and oscillators. I tried to find the component names of these, but google did not help. It will be great if some one could tell me which components are used in the board.

Thanks in advance.

[cutworth_wang · Accepted solution]

I think you can check BOM for the board.

http://cache.freescale.com/files/soft_dev_tools/hardware_tools/printed_circuit_boards/bom/TWR-K22F12...

[Paul_Tian]

Hi, Vishai

For 32.768KHz, R85 is DNP.

For 8MHz, R57 is need.

Best Regards

Paul

[vishalgirisagar]

Hi Zhe Tian,

I checked the data sheet of the crystal.

http://sg.element14.com/abracon/abm3b-8-000mhz-b2-t/crystal-8mhz-18pf-5-x-3-2mm/dp/2368190

According to the datasheet, the required Resistance is 200 ohms. But in the schematics of Freescale board, they have used 1M resistance. Can you please clarify on this?