Hi Avi,
We generally do not recommend crystals since there are so many vendors, and our chips can handle a wide range of frequencies. The MK10 crystal oscillator (EXTAL0/XTAL0) can operate in 2 modes - high gain and low power - and in 2 main frequency ranges - 32.768kHz and 3-30MHz. For the low frequency crystal, we recommend max ESR of 75k ohms and typical CL of 12.5pF. For a high frequency crystal we recommend max ESRs of 50 ohms for very high frequencies (32MHz) to 80 ohms for lower (8MHz) frequencies. Typical CL values are 18 to 20pF.
Smaller crystal packages tend to have higher ESR and lower CL, and should be used with caution. These can have longer startup times and may be difficult to tune with external load caps.
Regards,
John Suchyta
