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Crystal oscillator 15pF load

CommanderLake

Oct 2, 2012
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How can one verify a crystal oscillator has a 15pF load if any kind of testing equipment such as a scope probe adds capacitance to it, it seems impossible to verify the waveform without modifying it?
 

bertus

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Nov 8, 2019
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Hello,

What schematic do you use?
For what application is the oscillator?

Bertus
 

bertus

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Hello,

With the 15 pF load, you probably mean the test circuit in the datasheet:

cx259_test_circuit.png
The load is only there to show the driver capability.
Measuring the output to show the rise and fall times of the signal.

Bertus
 

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  • cx259.pdf
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CommanderLake

Oct 2, 2012
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Page 3, parameter Load: 15pF nominal.
How is it possible for one to validate such a small load?
 

majoco

Nov 10, 2019
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IMHO the load affects the waveform - 50ohms load makes the output into s a sine wave, 15pF might preserve a square wave shape.
As in most things - one test is worth a thousand opinions. ;)
 
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