Crystal Oscillator Circuit

Thus it utilizes the vibrating crystal s mechanical resonance which is made with a piezoelectric material for generating an electrical signal of a.

Crystal oscillator circuit.

The applied electric field will produce a mechanical deformation across some materials. The crystal usually quartz has a high degree of stability in holding con stant at whatever frequency the crystal is originally cut to operate. For example sine wave triangular waveform and square wave. In crystal oscillators the usual electrical resonant circuit is replaced by a mechanically vi brating crystal.

The crystal oscillators are therefore used whenever great stability is needed for example in communication trans mitters and. Crystal response to a step input13 4. This functions the popular pierce oscillator configuration. They generate the frequencies to be a base time.

Dc biasing of transistor and ic amplifier stages 21 4 6. When a voltage source is applied to a small thin piece of quartz crystal it begins to change shape producing a characteristic known as the piezo electric effect. Oscillator loop gain 19 4 4. Crystal s internal series resistancer 17 4 2.

Most of this will be made up by the two capacitors c1 and c2 although the remaining elements of the circuit will provide some capacitance. Reduced crystal voltage limits above 1 mhz 20 4 5. Typical colpitts transistor crystal oscillator circuit. The oscillators or frequency generators provide a waveform out in various forms.

This frequency is often used to keep track of time as in quartz wristwatches to provide a stable clock signal for digital integrated circuits and to stabilize frequencies for radio transmitters. The crystal oscillator circuit will be designed to present this capacitance to the crystal. The equivalent electrical circuit also represents the crystal action of the crystal. The basic components used in the circuit.

Hence quartz crystal oscillator circuits are superior compared to other resonators such as lc circuits turning forks and so on. It is quite possible to employ a single inverter to deliver the basis of a crystal oscillator and such a circuit appears in diagram below. Generally 8mhz crystal oscillator is used in microprocessors and microcontrollers. The inverter is biased into a linear amplifying mode by r1 and the crystal is linked amongst the input and the output of the circuit by means of tc1.

Circuit design characteristics 4 1. To obtain a very high level of oscillator stability a quartz crystal is generally used as the frequency determining device to produce another types of oscillator circuit known generally as a quartz crystal oscillator xo. 1 crystal oscillator circuit using 74ls04. To control an electronic circuit.

The crystal oscillator circuit like this get popular uses in digitals.