oscillators for 28x2 and 40x2

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Dippy

Moderator
They look like average crystals. Emphasis on 'look' as in 'complete guess'.

What does the Vendor's Data Sheet say? (haha).

Normally you would read the Data Sheet from the manufacturer to conifirm. This is one of the 'perils' of cheap unknown stuff from Ebay unknown vendors.

Assuming they are 'normal' crystals, you need to extra capacitors. One for each leg of the crystal. The values are typically 15pf to 22pF ceramic. Again, this is where the manufacturer's Data Sheet can confirm.

Below is the diagram from a PIC Data Sheet to show the connection.
The capacitors C1 and C2 are the capacitors I mentioned above.
(Ignore "Rs" for your 'average' crystals).

I have ADDED the chip pin numbers for 28X (18F2520).
For a 40X (4520) the chip pins would be 13 and 14.
i.e. where the Manual 1 shows resonator connections I believe (?)

If you are at all doubtful, then contact the Vendor and trust his word or pay a few extra cents and get them from a reputable vendor such as Farnell and a million others.
 

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hippy

hippy

Technical Support
Staff member
I agree with Dippy that they look like 'bog standard' two-leg crystals and will need the additional capacitors to work.

I would normally choose three-leg resonators over crystals for the convenience of being single component and ease of connection and I have not personally had any applications where resonators have not been just as good as crystals.
 
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yurif74

New Member
i can't find resonators on ebay and where i live customers doesn't have them :(
buy one or two resonators outside italy with shipping prices to italy is a kill.. they will cost about 7-8 euros each!!!!
 
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westaust55

Moderator
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