Crystal Oscillator Circuit Design

References and additional reading are listed below.

Crystal oscillator circuit design.

A crystal oscillator is an electronic oscillator circuit that is used for the mechanical resonance of a vibrating crystal of piezoelectric material. It can be used in the normal clock circuit. Changes in the phase angle will result in a change in the output frequency. Figure 2 4 shows the maximum drive power that can be put into a crystal without excessive heating and frequency shift in the crystal fig ure 2 5 shows the maximum permissible drive voltage across the crystal at exact series resonance.

It will create an electrical signal with a given frequency. A crystal oscillator is obviously designed to offer high firmness at a single frequency and is useless if a tuneable wide range oscillator is needed. Series resonant oscillator circuits are fairly basic and are typically used because of their small component count. Topics include load capacitance negative resistance startup time drive level dependency crystal aging and spurious modes.

My discrete pierce oscillator design tool can be found here. It consists of ic 4060 and ic 4013 the ic 4060 single acting oscillator and counter. There s no need for capacitors in the feedback loop for this type of circuit. The design of a crystal oscillator is very similar to the design of the colpitts oscillator we looked at in the previous tutorial except that the lc tank circuit that provides the feedback oscillations has been replaced by a quartz crystal as shown below.

A series circuit crystal oscillator uses a crystal that s designed to operate at its natural resonant frequency. This tutorial explains considerations to be addressed in a design of a simple crystal oscillator using at cut crystals. In this type of crystal oscillator design the filter consists of the crystal s equivalent model and the external load capacitors. These types of oscillator is practically invariably of the l c variety for functioning frequencies of a few hundred khz and above.

We ll examine the operational theory of crystal oscillators and design a discrete pierce crystal oscillator suitable for use as a local oscillator in an hf receiver. Ever wonder what goes in to the design of a crystal oscillator. The exact frequency at which an oscillator will operate is dependent on the loop phase angle shifts within the oscillator circuit. 3 cd4060 crystal oscillator circuit this is a 1hz oscillator circuit for a standard digital clock frequency size 1 hz or 2 hz.