PIC oscillator circuite

[Zedy]

hey!
Some simple question:
A series resistor, Rs, may be required for AT strip cut crystals, it is said in pic datasheet.
So... if I have Series resistance of 100 ? in Quartz datasheet, is it the same resistance what pic datasheet is talking about?

[Simon]

can you clarify the question  please ?

[Zedy]

can you clarify the question  please ?

sorry about my bad english,

but what I what to know is should I use this serial resistor?

[Simon]

The datasheet for the resistor and pic in question should show you the common basic diagrams for setting the crystal up

[djsb]

Post the page from the PIC data sheet AND the crystal data sheet (in PDF form) or cut and paste the relevant data here if you can (as an image) and we will be a lot clearer as to your meaning. Thanks.

[migsantiago]

hey!
Some simple question:
A series resistor, Rs, may be required for AT strip cut crystals, it is said in pic datasheet.
So... if I have Series resistance of 100 Ω in Quartz datasheet, is it the same resistance what pic datasheet is talking about?

Hi!

The datasheet says you should consult the datasheet for the crystal you're using. The manufacturer should say what resistor you should use.

I wouldn't care so much about that resistor. I've never had to use it before. 

[djsb]

These Microchip application notes may also be useful

• AN826, “Crystal Oscillator Basics and
Crystal Selection for rfPIC ®  and PIC ® 
Devices” (DS00826)
• AN849, “Basic PIC ®  Oscillator Design”
(DS00849)
• AN943, “Practical PIC ®  Oscillator
Analysis and Design” (DS00943)
• AN949, “Making Your Oscillator Work”
(DS00949)

David

[Zedy]

The datasheet says you should consult the datasheet for the crystal you're using. The manufacturer should say what resistor you should use.

I wouldn't care so much about that resistor. I've never had to use it before. 

crystal datasheet is very poor, and doesn't say anything

Post the page from the PIC data sheet AND the crystal data sheet (in PDF form) or cut and paste the relevant data here if you can (as an image) and we will be a lot clearer as to your meaning. Thanks.

I usually don't care about oscillator, but this time I need very precise frequency.

[tecman]

I believe your datasheet data is referring to the equivalent series resistance of the crystal at resonance.  Usually a series resistor is not required, and as stated only for crystals with low drive power requirements.

I would not use a resistor.

paul

[Zedy]

I believe your datasheet data is referring to the equivalent series resistance of the crystal at resonance.  Usually a series resistor is not required, and as stated only for crystals with low drive power requirements.

I would not use a resistor.

paul

Thank you, it was, what I wanted to hear