Crystal Oscillator - synchronized two crystals

Possibly a small value capacitor between the two tank circuts ?

That is, driving the two crystal inputs with another oscillator circuit does not work...

The only circuitry visible is the crystal, the oscillator circuit is internal to the part.

Yes, but not for a person who calls himself "nicefarts."

John

You could use a PLL and a voltage controlled crystal oscillator.

Is there a good reason why you can't just use one oscillator?

There are two units, both with their own oscillators build in. The only parts exposed are the crystals. I want to sync the two crystals (which would then sync the oscillators), or the just two oscillators with a faked crystal.

It sure reads like he doesn't understand how to do that, hence his perceiving that he needs a far more complicated method, ie synchronizing to oscillators.

It sounds more like a drive problem, or maybe he's trying to feed an external oscillator into the wrong crystal pin, so instead of connecting to the input of the gate that's being used as an oscillator in the IC, he's connecting to the output of that gate, which likely would cause drive problems.

Michael

Most any crystal's response can be overridden by a strong enough external circuit.

The request makes zero sense whatsoever.

Perhaps if you shared the IC part numbers, someone motivated could look at the data sheets?

Normally with parts like this there's an amplifier built in to the chip, and it's as easy as pie to drive the input side. Something is odd about your setup, and you're not giving us enough information to figure out what.

Then take a 100 pF capacitor, solder a wire to each lead, and touch one cap lead to one pin of one crystal, and the other lead to one pin of the other crystal. Try 1-1, 1-2, 2-1, and 2-2, and use whatever works best.

You might need a little breakout socket to access the crystal pins.

Good Luck! Rich

Perhaps he thinks he or she is a supremely enlightened being from the planet Tersurus ~ except oops, they're all dead ~

-jiw

So just buy one in china...

On a sunny day (20 Feb 2007 13:41:03 -0800) it happened snipped-for-privacy@gmail.com wrote in :

If it is 2 micro controllers, these each have an oscillator out, and an oscillator in pin. Remove one xtal, also the 2 caps to ground if they are there on the same chip. Connect osc out of the one with the xtal to osc in of the one you just stripped of the xtal.

So you get his:

| Chip 1 | Chip 2 | | | osc in osc out | osc in osc out

---------------------- ------------------------------ | | | | | no connection |--||||----0------------------------------- | | | | === === | | /// ///