Crystal Oscillator Circuit

The crystal oscillators are therefore used whenever great stability is needed for example in communication trans mitters and.

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. In crystal oscillators the usual electrical resonant circuit is replaced by a mechanically vi brating crystal. The crystal oscillator circuit usually works on the principle of the inverse piezoelectric effect. Load impedance across the crystal terminals 18 4 3.

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. 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. Dc biasing of transistor and ic amplifier stages 21 4 6. The equivalent electrical circuit also represents the crystal action of the crystal.

The applied electric field will produce a mechanical deformation across some materials. For example sine wave triangular waveform and square wave. Typical colpitts transistor crystal oscillator circuit. They generate the frequencies to be a base time.

Hence quartz crystal oscillator circuits are superior compared to other resonators such as lc circuits turning forks and so on. The crystal oscillator circuit will be designed to present this capacitance to the crystal. Circuit design characteristics 4 1. Crystal s internal series resistancer 17 4 2.

The oscillators or frequency generators provide a waveform out in various forms. 1 crystal oscillator circuit using 74ls04. The crystal oscillator circuit like this get popular uses in digitals. Reduced crystal voltage limits above 1 mhz 20 4 5.

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. Oscillator loop gain 19 4 4. A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a precise frequency. This functions the popular pierce oscillator configuration.

The basic components used in the circuit. 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. The crystal usually quartz has a high degree of stability in holding con stant at whatever frequency the crystal is originally cut to operate. 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.