Crystal Oscillator Circuit Diagram

Generally bipolar transistors or fets are used in the construction of crystal oscillator circuits.

Crystal oscillator circuit diagram.

They generate the frequencies to be a base time. 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 response to a step input13 4. The quartz crystal oscillator circuit diagram consists of series resonance and parallel resonance i e two resonant frequencies.

The series and parallel resonant frequencies are represented by fs and. The above figure is a 20psc new 16mhz quartz crystal oscillator and it is one kind of crystal oscillators that works with 16mhz frequency. In our previous articles we explain hartley oscillators and colpitts oscillators in brief. In crystal oscillators the usual electrical resonant circuit is replaced by a mechanically vi brating crystal.

The crystal usually quartz has a high degree of stability in holding con stant at whatever frequency the crystal is originally cut to operate. To control an electronic circuit. Therefore the gain of the transistor limits the maximum values of c1 and c2. The crystal oscillators are therefore used whenever great stability is needed for example in communication trans mitters and.

Dc biasing of transistor and ic amplifier stages 21 4 6. The oscillators or frequency generators provide a waveform out in various forms. This is very identical in functioning to the pierce oscillator which was explained previously the difference being that a centre tapped l c circuit is employed instead of the capactively centre tapped crystal. Here we are going to explain crystal oscillator and its circuit diagram in brief.

The circuit diagram of a cmos hartley oscillator is shown in below diagram. Circuit design characteristics 4 1. Load impedance across the crystal terminals 18 4 3. 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 circuit diagram above of the colpitts crystal oscillator circuit shows that capacitors c1 and c2 shunt the output of the transistor which reduces the feedback signal. Oscillators which utilizes the inductor l and capacitor c in their circuit are called as lc. Oscillator is an amplifier with the positive feedback and it converts dc input signal into ac output waveform with certain variable frequency drive and certain shape of output waveform like sine wave or square wave etc by using the positive feedback instead of input signal. Crystal s internal series resistancer 17 4 2.

1 crystal oscillator circuit using 74ls04. Crystal oscillator circuit diagram. Reduced crystal voltage limits above 1 mhz 20 4 5. The output amplitude should be kept low in order to avoid excessive power dissipation in the.

The crystal oscillator circuit like this get popular uses in digitals. If the reactance produced by capacitance c1 is equal and opposite to the reactance produced by inductance l1 then the series resonance occurs.