(Fig. 1) shows the schematic of both metal can type and ceramic SMD type resonators and its symbol. The electrical properties of the unloaded resonator can be approximately expressed in Butterworth-Van Dyke (BVD) equivalent circuit as shown in Fig.5 when operating near a resonance frequency zone.
(Fig. 1)
(a) Metal can type resonator
(b) Ceramic SMD type resonator
(c) Symbol of crystal usnit
By using the four parameters shown in (Fig .2) the major electrical properties of a crystal resonator and of a oscillator consisting of the crystal resonator are described as follows.
﹝Fig.2﹞Effective Circuit of Crystal
Quartz Crystal Units
