Crystal oscillator 14 / 4 / 2014 Welcome Mohammad Alsharafi 230

Sinusoidal Oscillators Electronics circuits Transistor AMP OP AMP Timers Sinusoidal oscillator Crystal oscillator

Introduction Why we use the oscillator? Why we use it in the lap? What is this device ? to give us a wave that we can adjust its frequency and shape to give us a wave that we can adjust its frequency and shape Function signal generator What is the different between them ?

Discuss about the answer as partner for 5 min. Partner work What is the different between function generator & oscillator circuit? Discuss about the answer as partner for 5 min.

To avoid this issue we should use a heat sink. Stability effects Temperature : Rising of Temperature will change the frequency (f) and the gain (A). To avoid this issue we should use a heat sink.

Oscillator stability Voltage source : The value of voltage source is not stable by time, so the frequency will change. By using a voltage regulator the voltage will not change, and so is frequency.

Oscillator stability The load: When we change the load the frequency will change. To solve this problem we should put a buffer between the oscillator and the load .

Oscillator stability The quality factor (Q) : To have an accurate oscillator, the Q should be between 104 and 106. To have this number of Q, the impedance of the capacitor and inductor should be very small, and that is impassible. To avoid this problem we should connect a crystal between the output and noninverter input of the oscillator circuit.

Crystals What is special about these crystals? Topaz Tourmaline Quartz Crystal Oscillator Crystals Topaz Tourmaline Quartz What is special about these crystals? Sucrose Berlinite

Crystal Oscillator Piezoelectric effect piezoelectricity means voltage resulting from pressure, or vibration resulting from voltage. There are thousands of application stand on this effect (such as cigarette lighter) . video

Exercise 1 Part 1 Why we use a crystal in the oscillator circuit? Crystal Oscillator Exercise 1 Part 1 Why we use a crystal in the oscillator circuit? To have an accurate oscillator. What is special about some crystals we use them in electronics ? The piezoelectric effect .

Exercise What is piezoelectric effect ? Crystal Oscillator Exercise What is piezoelectric effect ? voltage resulting from pressure, and vibration resulting from voltage.

Crystal Oscillator Exercise Part 2 We use voltage regulator in the oscillator circuit to ……………….. . Have an accurate oscillator. Avoid The heat. Avoid Changing in the load. Avoid Changing in voltage source.

Crystal Oscillator Exercise What is the best value of the quality factor that will makes an accurate oscillator. 105 103 104 107

Crystal Oscillator Exercise The man on the video talked about the error of the crystal oscillator, so that error is……. . One minute per a month. One minute per two years. 3 minutes per 3 years. Nothing correct. (what is the answer?)

Quartz Crystal Oscillator Topaz Tourmaline Quartz is the second most abundant mineral in the Earth's continental crust. It is made up of SiO4 silicon–oxygen tetrahedra. There are many kind of quartz. Quartz Sucrose Berlinite

Quartz oscillator Quartz oscillator is as like as any other electronics component. It has symbol and different values. Its values start from a few kilo Hertz to hundreds of hertz. equivalent circuit symbol

Each group will do the task In the whiteboard for Crystal Oscillator Exercise 2 Each group will do the task In the whiteboard for 5 min Group of 3 Draw the symbol and the equivalent circuits of the quartz oscillator.

Crystal oscillator 14 / 4 / 2014 Thank you Mohammad Alsharafi 230