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.

Crystal oscillator circuit design.

My discrete pierce oscillator design tool can be found here. 3 cd4060 crystal oscillator circuit this is a 1hz oscillator circuit for a standard digital clock frequency size 1 hz or 2 hz. 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. 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.

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. The exact frequency at which an oscillator will operate is dependent on the loop phase angle shifts within the oscillator circuit. A series circuit crystal oscillator uses a crystal that s designed to operate at its natural resonant frequency. 200 000 r is the largest single factor in oscillator design and dominates the design of every oscillator circuit.

Of the frequency determined by the resistor and external capacitor. References and additional reading are listed below. Changes in the phase angle will result in a change in the output frequency. Series resonant oscillator circuits are fairly basic and are typically used because of their small component count.

Ever wonder what goes in to the design of a crystal oscillator. It will create an electrical signal with a given frequency. In this type of crystal oscillator design the filter consists of the crystal s equivalent model and the external load capacitors. It can be used in the normal clock circuit.

Topics include load capacitance negative resistance startup time drive level dependency crystal aging and spurious modes. There s no need for capacitors in the feedback loop for this type of circuit. These types of oscillator is practically invariably of the l c variety for functioning frequencies of a few hundred khz and above. This tutorial explains considerations to be addressed in a design of a simple crystal oscillator using at cut crystals.