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How to increase TCXO output?
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rcbuck:
I have a 16.384 MHz TCXO which has the standard 0.8 volt Pk-Pk clipped sine wave output. I need to increase that level to ~3 volts to drive a SN74LVC1G14 inverter. I tried a single transistor common emitter amplifier but didn't have any luck with that. I have decided the best way to handle this is a high speed comparator. That would give me a nice square wave output.

I am going to use the STMicroelectronics TS3011 part. If I am interpreting the data sheet properly, it will work. On page 10, Figure 9, the upper trip point appears to be slightly more than 1 mV over the reference level. The lower trip point is slightly less than 1 mV below the reference. So If I set the reference to about 300 mV the TCXO should easily drive the comparator.

Is my thinking correct as to how the comparator works?
edavid:
If it's a 1-off circuit, I suggest just AC coupling it.  Use a 10K pot to bias the inverter input to the right place.  It may not meet absolute worst case specs, but it should work.

Otherwise, you could use an unbuffered 74LVC inverter as a 10X amplifier.
rcbuck:
I may want to build more than 1 unit. If I remember correctly, I think I tried the inverter biasing circuit in a past project and it made the inverter run hot. I would also be somewhat concerned about reliability of this method due to temperature excursions.

I've never had any luck with 10X inverter amplifiers. The output level tended to follow the input level. Perhaps I had the circuit wrong. I just used a 10 meg resistor as the feedback element.

Do you foresee any issues with using the TS3011?
floobydust:
74LVC1G14 worked for me, (but not for your 100kHz oscillator), more discussion here:
https://www.eevblog.com/forum/projects/level-translate-the-output-of-a-tcxo-crystal-oscillator-module/msg1550348/#msg1550348
74LVC1GX04 looked like it has enough gain.

An AC-coupled comparator with some hysteresis would work too.
edavid:

--- Quote from: rcbuck on April 30, 2019, 03:04:08 am ---I may want to build more than 1 unit. If I remember correctly, I think I tried the inverter biasing circuit in a past project and it made the inverter run hot.

--- End quote ---
Since it's a Schmitt trigger inverter, that's not an issue.


--- Quote ---I've never had any luck with 10X inverter amplifiers. The output level tended to follow the input level. Perhaps I had the circuit wrong. I just used a 10 meg resistor as the feedback element.

--- End quote ---
I've never had any problem with them  :-//


--- Quote ---Do you foresee any issues with using the TS3011?

--- End quote ---
Not really, it's just overkill.
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