how to use a crystal oscillator???

[rsashwinkumar]

wI want to use a crystal-oscillator to generate a sine wave of 200Mhz. Now i purchase a crystal oscillator from the shop. How should i use it to obtain sinusoidal oscillations at 200Mhz? My doubt basically is that, will a newly bought crystal oscillator produce a square wave or a sine wave output??

Then, whatever be the output, how to use it to get sinusoidal output???

Plz help me out...

 

[chuckey]

if you purchase a 200MHz crystal oscillator from a shop, there will be a data sheet available for it. If the one you purchase has a square wave output, then a simple filter will reject the harmonics, leaving you with a sine wave.
Frank

 

[rsashwinkumar]

So so you mean to say that, some crystals produce square and some sine wave ???

 

[Qaisar Azeemi]

i think piezo crystal is a natural thing and all natural phenomenon are continuous, a crystal oscillator will generate continuous sine wave signals. the internal molecular structure provides the behavior of RLC circuit which will always provide a continuous sine wave signal.

producing signal with a quartz crystal is not a difficult task. u have to provide voltage between two phases of crystal to produce a frequency. this frequency may be provided at the base of a transistor to produce the required frequency at the out put.

in order to produce clocking signals for microcontroller you have to filter the frequency to get clock signals which are directly fed to the oscillator inputs of the controller/processor.

plz see the link below that may give a detail idea about frequency generation using a crystal oscillator.

Quartz Crystal Oscillator and Quartz Crystals

Regards

 

[chuckey]

The voltage across the crystal is always a sinewave. The output from the oscillator could be an amplified version of this sinewave or it could be a squarewave.
Frank

 

[keremcant]

hi Chuckey,
I checked the datasheet of this voltage controlled oscillator but could not find wether the output is a sine or a square wave.
How can I understand it?
part: CVCO33CL-0110-0150
datasheet is in specifications link in Crystek Microwave
thanks

 

[chuckey]

As the datasheet says that the second harmonic is > 10DB down, it is saying that its a distorted sinewave. If it was a square wave it would give a risetime in the spec.
Frank

 

[fareen]

i m too working with the oscillator
im unable to find dtasheet of a 15Mhz oscillator??

 

[keremcant]

chuckey, thanks for your reply.
from what you have said, I understand -10dBc is not enough. Then what should be the appropriate value of the harmonic suppression so that the oscillator can be assumed to be a pure sine wave oscillator.
Thanks again