Crystal Oscillator - synchronized two crystals

[[email protected]]

Is there a way to synchronize two crystals for two different crystal
oscillator circuits. Driving the two crystal inputs does not work, the
circuit draws too much current.

 

[Lefty]

Is there a way to synchronize two crystals for two different crystal
oscillator circuits. Driving the two crystal inputs does not work, the
circuit draws too much current.

Possibly a small value capacitor between the two tank circuts ?

 

[[email protected]]

Is there a way tosynchronizetwo crystals for two differentcrystal
oscillator circuits. Driving the twocrystalinputs does not work, the
circuit draws too much current.

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

 

[[email protected]]

Possibly a small value capacitor between the two tank circuts ?

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

 

[John Larkin]

Is there a way to synchronize two crystals for two different crystal
oscillator circuits. Driving the two crystal inputs does not work, the
circuit draws too much current.

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

John

 

[Gareth]

Is there a way to synchronize two crystals for two different crystal
oscillator circuits. Driving the two crystal inputs does not work, the
circuit draws too much current.

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

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

--

 

[[email protected]]

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

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

--
-----------------------------------------------------------------------
To reply to me directly:

Replace privacy.net with: totalise DOT co DOT uk and replace me with
gareth.harris

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.

 

[Michael Black]

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

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

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

 

[Don Lancaster]

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.




--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Tim Wescott]

Is there a way to synchronize two crystals for two different crystal
oscillator circuits. Driving the two crystal inputs does not work, the
circuit draws too much current.

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.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html

 

[Rich Grise]

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

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

 

[James Waldby]

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

Perhaps he thinks he or she is a supremely enlightened
being from the planet Tersurus ~ except oops, they're all dead ~
http://en.wikipedia.org/wiki/Doctor_Who_and_the_Curse_of_Fatal_Death#Synopsis

-jiw

 

[Fred Bartoli]

[email protected] a écrit :

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.

So just buy one in china...

 

[Jan Panteltje]

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.

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-------------------------------
| | | |
=== ===
| |
/// ///