Hi all,

I need to find the equivalent BVD model of a quartz crystal which is being fabricated by one of my labmates. All I have is the area of the electrode (dia. 50 um) and the thickness (10um) and I need to find the RLC values which can then be plugged into a Spice simulation of an oscillator circuit.

Could someone please help me out with this!

Thanks in advance.

 

Indeed I can. From the ARRL Handbook:

A crystal consists of a series resistance, capacitance, and inductance. A capacitor (holder capacitance) is in SHUNT with the three above series components.

For a 1MHZ crystal:

Series L=3.5 Henry
Series C=.007 picofarads
Series resistance=340 ohms
Shunt capacitance=3 picofarads



These values can be essentially scaled for any fundamental crystal in the H.F. range. Notice the HUGE L/C ratio of the series elements....this is where the Q comes from!

Eric