#4 - TCXO frequency reference teardown
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- Опубліковано 25 сер 2024
- Teardown of a Monitor 10MHz 1ppm TCXO oscillator, which failed. Unfortunately I couldn't find any information on the WF10192 chip, which I foolishly called an op-amp in the video. Seems like some kind of a frequency divider.
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With some luck, "B4" SOT23 is an ITT "BB404B", a varactor diode, and what is connected to pin 2 is an NTC. The output voltage of the opamp then steers the varactor diode bias to change the xtal detuning to offset its temperature dependence.
The white trimmer is a trim capacitor to calibrate the nominal frequency.
good tutorial. Going into details and keeping it simple
The strips are resistors, I usually see them as trim resistors that are trimmed with a laser at the factory but I don't think I can see a mark in these, might have just been to save space.
As far as I have understood the TCXO uses a varactor to pull the crystal frequency based on the measured temperature. I would also think that the sealed adjustment next to the crystal does the manufacturing calibration of the frequency. And the zero-ohm resistor jumpers select the rate of drift compensation. Just a guess, of course. Sure there would be actual more authoritative info somewhere, if I tried to look around.
Thanks! I was wondering what was inside too, before buying one to experiment with.
WF10192 is from winbond, taiwan
there are sooooooo many tcxo models, some with sinus, hcmos, lvcmos, ttl and so on, I wish to update a transceiver that has a simple crystal ocsillator with a TCXO but I have no clue to to direct replace a crystal by a TCXO, which one to chose...
hello can it work ok with BUC
I wonder if those carbon looking tracks where to do with triming ?
hello friends, where are the resistor are missing on the pads?, i've noitce it on alot of boards too. thanks.
my your understand no
I have the same HP counter as you. Were you ever able to use these 10mhz TCXOs with your counter for better accuracy? I have bought the exact same part for the same reason.
I bought a couple of OCXOs after that: ua-cam.com/video/0UT6smae8M0/v-deo.html
But I never got around to putting one of them into the counter (yet).
FeedbackLoop When I get mine, I'm going to build it into a metal box and connect a cable to the counter and set the switch to external so I don't have to modify the counter. Mine seems to be pretty accurate anyway. Thanks for the videos.
why is this a TCXO? where is the heater?
Heaters are in OCXOs (O is for oven). In TCXOs the components are kept at the same temperature as much as possible by putting them into an enclosure, and some measures are taken in the design to compensate the temperature drift. For example, if the crystal drifts up with the rise of the temperature, have some other component in the adjustment path drifting in such a way so that it pulls the adjustment down.
20MHz
I have seen some of your other videos and I believe you are a accomplished engineer. I do wonder though, why your approach is lacking more depth? You seem to be asking more questions than answers that I believe you know. It makes watching this a bit frustrating.
This is my video #4 produced about 4 years ago. I hope I have improved since then.
Seems fine to me. Only stupid people fail to ask questions.
Seems fine to me too. Only stupid peeps don't ask questions. Why don't YOU make a video about this? Then we can go round-d-round too.
Говорил бы уже по русски)) Чё кривятся?