Question on Linear Technology AN12.

[hamster_nz]

I'm looking at the TXCO design in https://www.analog.com/media/en/technical-documentation/application-notes/an12fa.pdf, and see something I don't understand.

In figure 6, is the 100k resistor on the Collector of the transistor supposed to be there? (see attached image)

What does it do? On a breadboard it actually works of the collector is connected to 5V, but not with the 100k....

[Conrad Hoffman]

That almost has to be a typo. Probably wanted 100 ohms or so.

[floobydust]

Strange, it's 100R in the Oct. 1985 version with 30k/100k for the data slicer.

edit: From rare goldmine, 1990 Linear Applications Handbook, in a time before pdf's and the Internet became a thing, it is 100R with 100k/100k but 0.01uF for the data slicer.
Something is changing part values around, I've seen three different versions.

[glarsson]

Why is the AN calling it a TXCO? Also a typo or a different reality?

[hamster_nz]

Why is the AN calling it a TXCO? Also a typo or a different reality?

In the to left of the schematic there is a thermistor that generates a 0-4V signal that is used to nudge the XTALs frequency.

[hamster_nz]

Strange, it's 100R in the Oct. 1985 version with 30k/100k for the data slicer.

edit: From rare goldmine, 1990 Linear Applications Handbook, in a time before pdf's and the Internet became a thing, it is 100R with 100k/100k but 0.01uF for the data slicer.
Something is changing part values around, I've seen three different versions.

Hummm... 100 ohm makes sense...

Thanks for checking this!

[glarsson]

In the to left of the schematic there is a thermistor that generates a 0-4V signal that is used to nudge the XTALs frequency.

Yes, but that makes the design a TCXO, not a TXCO. Whatever that is.

[hamster_nz]

In the to left of the schematic there is a thermistor that generates a 0-4V signal that is used to nudge the XTALs frequency.

Yes, but that makes the design a TCXO, not a TXCO. Whatever that is.

Oh dear! I didn't see that...

Maybe they let an intern update the appnote?