Crystal Oscillator Circuit

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.

Crystal oscillator circuit.

The basic components used in the circuit. 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. The crystal oscillator circuit like this get popular uses in digitals. Crystal s internal series resistancer 17 4 2.

The applied electric field will produce a mechanical deformation across some materials. 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. 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. Crystal response to a step input13 4.

Thus it utilizes the vibrating crystal s mechanical resonance which is made with a piezoelectric material for generating an electrical signal of a. Typical colpitts transistor crystal oscillator circuit. Oscillator loop gain 19 4 4. 1 crystal oscillator circuit using 74ls04.

This functions the popular pierce oscillator configuration. 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. The crystal oscillators are therefore used whenever great stability is needed for example in communication trans mitters and. Hence quartz crystal oscillator circuits are superior compared to other resonators such as lc circuits turning forks and so on.

The oscillators or frequency generators provide a waveform out in various forms. The crystal oscillator circuit usually works on the principle of the inverse piezoelectric effect. They generate the frequencies to be a base time. For example sine wave triangular waveform and square wave.

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. In crystal oscillators the usual electrical resonant circuit is replaced by a mechanically vi brating crystal. The equivalent electrical circuit also represents the crystal action of the crystal. To control an electronic circuit.

Generally 8mhz crystal oscillator is used in microprocessors and microcontrollers. Load impedance across the crystal terminals 18 4 3. The crystal usually quartz has a high degree of stability in holding con stant at whatever frequency the crystal is originally cut to operate. Dc biasing of transistor and ic amplifier stages 21 4 6.

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.