Crystals are available for various frequencies. If you need a crystal different from those available, you must set the parameters listed in the following table.

Parameters

Parameter Description Units Default
FREQ The nominal output frequency of the crystal. Hz 1Meg
RS The resistance exhibited by the crystal at the series resonant frequency. Ω 750
C Shunt capacitance in Farads. This value is the combination of the capacitance due to the electrodes on the crystal plate and stray capacitances arising from the crystal holder/enclosure. Farads 13pF
Q The quality factor of the equivalent electrical circuit model for the crystal. This essentially is the ratio of energy stored to energy dissipated for the circuit and can be further defined as the ratio of the reactance (series motional inductance and capacitance) to the series resistance at the resonant frequency.   1000