1. Crystal oscillator
14 / 4 / 2014
Welcome
Mohammad Alsharafi

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

3. 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 ?

4. 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.

5. 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.

6. 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.

7. 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 .

8. 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.

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

10. 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

11. 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 .

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

13. 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.

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

15. 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?)

16. 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

17. 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

18. 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.

19. Crystal oscillator
14 / 4 / 2014
Thank you
Mohammad Alsharafi