4-56
Text Box: Frequency Change (parts in 109)
Frequency Change (parts in 109)
80
60
40
20
0
-20
100
200
300
400
500
600
700
5 MHz AT
3 diopter
10 MHz SC
2 diopter
10 MHz SC
1 diopter
10 MHz SC
10 MHz BT
Crystal Current (microamperes)
Frequency vs. Drive Level
   Frequency varies as the current amplitude squared; f = f0 (1 + aI2), where a is a constant that is a function of the design, i.e., the appropriate nonlinear elastic constant for the resonator type used, and I is the current.
   Useful drive levels are limited at the high end by the nonlinearities of quartz, and at the low end by noise (or defects, as discussed on the next page).


J. A. Kusters, "The SC Cut Crystal - An Overview," Proc. 1981 IEEE Ultrasonics Symposium, pp. 402-409.

J.J. Gagnepain and R. Besson, “Nonlinear Effects in Piezoelectric Quartz Crystals,” in Physical Acoustics, Vol. XI, pp. 245-288, W.P. Mason & R.N. Thurston, editors, Academic Press, 1975

R. L. Filler, "The Amplitude-Frequency Effect in SC-Cut Resonators," Proc. 39th Annual Symposium on Frequency Control, pp. 311-316, 1985, IEEE Catalog No. 85CH2186-5.

D. Hammond, C. Adams, and L. Cutler, "Precision Crystal Units," Proc. 17th Annual Symposium on Frequency Control, pp. 215-232, 1963, AD-423381.