I need to create a osc. that outputs 11.289 Mhz (CD audio). And preferably one that outputs a very square output.
The following image is from a 1994 vocational college textbook.
Note it specifies a 74LS04 inverter. And 0.5-10Mhz.
All I have is a Fairchild 74AC04.
I connected the ckt exactly as shown; 5vdc power. I tried two different 11.289 xtals. But I could only get a max of 330khz at the second inverter. Nothing out the third.
The textbook ckt may be missing some components, like the two typical 30pf caps to ground.
Any way to mod the textbook ckt to get that square 11.289 mhz ?
Thx!

 

I did connect two 39pf caps to gnd, and now I don't even have the 330khz .

https://www.circuitbasics.com/wp-content/uploads/2020/09/cmos_osc.png
https://www.circuitbasics.com/crystal-oscillators/

 

What series capacitance does your crystal call for? 39p is higher than I ever use, try 22.

Also, try a 1K between the output of the gate and the crystal. And try lowering the 1.5M bias resistor to 1M or 560Kz.

 

11.289MHz might be pushing it a bit for a 4069. You would be better with a 74HCU04. (And make sure it has the U - that is important)
(Why a 10MHz crystal, when you want 11.289MHz?)
I use 10M resistor, and 22pF or 15pF caps, and it never fails to oscillate.
You might need a series resistor to give some more phase shift on lower frequency crystals, but the output resistance of a 74HCU gate is always enough at >10MHz.
Gates with lower output resistances (74AC) might need extra resistance.

 

Hey Folks!
Based on your comments, I may have not presented the issue clearly.

The second post with the schematic is simply an example of a ckt with the two caps in question and somewhat similar topology. That's not what I am using.
I am using the ckt in first thread post, with a 11.289 mhz xtal, and a 74AC04 Fairchild inverter. To that I've also experimented with two 39pF caps (as shown in 2nd post). I still can't get it work!
Apologies for confusion -- just my own laziness!

 

I am using the ckt in first thread post,

Don’t.
Use the circuit in post #2 with a 74HCU04.

The other circuits are designed for bipolar TTL.

 

The circuit in post #1 is for a series resonant crystal. Is that what you have, or do you the much more common parallel resonant type?

 

Unless the load for your oscillator is TTL compatible, move to the CMOS circuit.

 

The circuit in post #1 is for a series resonant crystal. Is that what you have, or do you the much more common parallel resonant type?

Not sure.
I have a couple of typical two-pin xtals.
My bottom line is to have a very square 11.289 MHz osc. waveform.
I guess a I need a working circuit design, and not something "theoretical" out of college book., like the one I found!

 

Not sure.
I have a couple of typical two-pin xtals.
My bottom line is to have a very square 11.289 MHz osc. waveform.
I guess a I need a working circuit design, and not something "theoretical" out of college book., like the one I found!

If it doesn't say "series resonant" then it will be parallel resonant. If you use the series resonant circuit, it will oscillate perfectly nicely but at slightly the wrong frequency. I presume you want your music to be pitch perfect, not a semitone sharp?

 

I suppose I could use dedicated xtal driver like:
sn74lvc1gx04
... or ...
Motorola MC12061P

 

If it doesn't say "series resonant" then it will be parallel resonant. If you use the series resonant circuit, it will oscillate perfectly nicely but at slightly the wrong frequency. I presume you want your music to be pitch perfect, not a semitone sharp?

Most digital audio devices (CD players, etc) have two-pin xtal attached to Xout and Xin on a processor IC (like a decoder or servo IC). I assume these are typical Pierce.
See page 4 here:
http://tentlabs.com/Components/XO/assets/XO23mounting.pdf

 

74LVC1GU04 will do the job. It's not a "dedicated crystal driver" - it's just an unbuffered gate.
If you only have the 74HC04, you could make the oscillator with a JFET and just use the AC04 to square it up.

 

Most digital audio devices (CD players, etc) have two-pin xtal attached to Xout and Xin on a processor IC (like a decoder or servo IC). I assume these are typical Pierce.
See page 4 here:
http://tentlabs.com/Components/XO/assets/XO23mounting.pdf

Yes - Pierce oscillator.

 

74LVC1GU04 will do the job. It's not a "dedicated crystal driver" - it's just an unbuffered gate.
If you only have the 74HC04, you could make the oscillator with a JFET and just use the AC04 to square it up.

Pretty new to this ... so I'm trying to get up to speed
Most of the JFET osc ckts I've seen are 1-10MHz. I need at least 11.289 MHz (and perhaps up to 50 Mhz for later projects).
Will this work:

Source:
https://www.simplecircuitdiagram.com/510-jfet-pierce-crystal-oscillator/
Also, what value for RFC would you suggest?

 

Pretty new to this ... so I'm trying to get up to speed
Most of the JFET osc ckts I've seen are 1-10MHz. I need at least 11.289 MHz (and perhaps up to 50 Mhz for later projects).
Will this work:

Source:
https://www.simplecircuitdiagram.com/510-jfet-pierce-crystal-oscillator/
Also, what value for RFC would you suggest?

It will work with a resistor, it will probably work a lot faster than 10MHz.
https://www.qsl.net/g3oou/solidstatecircuits2.html
https://www.ti.com/lit/an/snoa620/snoa620.pdf?ts=1686658426126&ref_url=http%3A%2F%2Fwww.pa3fwm.nl%2F (see page 9)
Here's a nice application notes from TI about gate oscillators
https://www.ti.com/lit/an/szza043/szza043.pdf?ts=1686642121903&ref_url=https%3A%2F%2Fwww.ti.com%2Fproduct%2FSN74LVC1G14

 

It will work with a resistor, it will probably work a lot faster than 10MHz.

Thanks ... but what resistor and where? Also, what value for RFC would you/anyone suggest?

 

This is a fundamental frequency oscillator circuit.If you want it to oscillate at the crystal's native frequency, the the value of the RFC is not very important - just chose something over a few hundred uH for 11 MHz. If you are using an overtone the drain should be driving a resonant circuit instead of a choke so you the the desired harmonic out.

 

Thanks ... but what resistor and where? Also, what value for RFC would you/anyone suggest?

A resistor instead of the RFC

 

A resistor instead of the RFC

Uh .. .value? Sorry ... still a newbie here.