Pierce Oscillators

[JasonL220]

i've been looking at the diagrams on this **broken link removed** and an not sure what value to use fo rthe resistor and capasitors to get a certain requency, could someone please explain?

thanks

 

[stevez]

Amateur radio publications are likely to provide some good info.

 

[Papabravo]

The values of the resistor and the capacitor have relatively little to do with the frequency of operation. The frequency of oscillation is an intrinsic property of the particular quartz crystal. The resistors are used to bias the amplifier into the linear range and prevent the amplifier from overdriving the crystal. The capacitors provice some load in order to ensure that the oscillator starts and stabilizes within a resonable period of time. Some designers can "pull" the frequency a little bit by changing the load capacitance. This technique is seldom used anymore because there are better ways to get what you want. These mostly involve the use of a phase locked loop or a frequency synthesizer.

 

[audioguru]

The datasheet for the quartz crystal or the ceramic resonator has a "standard" circuit that the manufacturer uses to test their product.