Need some help identifying oscillator pinout - Page 1
Forum section: electronics / general

author: shawty
author_rank: Regular Contributor
timestamp: September 03, 2023, 03:34:17 pm
content: Apologies if there's a better forum thread for this, please move it if there is.While clearing out some old boxes of electronics I found some very old oscilator circuits, the all in one can veriety that you hook up to power and they provide a square wave on one of the pins.I can see from the markings on top that one is 8mhz the other is 16mhz, and they are at least 4 times the size the more modern ones are, they are also considerably hevier.They have 5 pins on the bottom, I've tried hooking them up same way I do the newer 4 pin veriety, but getting nothing out of them on the scope.Scope is set up all ok, as it's giving me a trace on the newer ones I'm using for reference.Bing/Google.... absolutely useless (As sadly is usually the case these days), well unless I want to buy a clock....Anyway here are some photos of the devices, if anyone knows the pinout, or even has a data sheet I love to see them.https://imgur.com/a/WNIGFHuI don't know why the individual imgur image links are not showing, but if you click on the anchor link that is showing above this line, it'll take you to the full page on imgur where I posted them all.Many thanksShawty

author: CountChocula
author_rank: Unknown
timestamp: September 03, 2023, 08:17:06 pm
content: I think these are temperature-compensated oscillators. It looks like the 16MhZ one is voltage-controlled as well; not sure about the 8MHz one. In addition to a supply and ground, it also needs a control voltage that can be used to trimmed the exact oscillation frequency. I think that the pinout is as follows (but please don't blame me if you end up frying the component, I may be completely wrong!):1 - Output2 - GND (also connected to the can, so you can verify as a basic sanity check)3 - Control voltage input4 - Reference voltage5 - VCCAs I understand, you can use the reference voltage on these cans to program the control voltage pin using a pot. No idea what VCC might be… I would perhaps start around 5V and work my way up, as some of these things run at 12V.—CC

author: DimitriP
author_rank: Super Contributor
timestamp: September 03, 2023, 10:46:44 pm
content: QuoteBing AND google want you to take them apaaaht!!!And post pictures!

author: shawty
author_rank: Regular Contributor
timestamp: September 03, 2023, 11:07:09 pm
content: Quote from: DimitriP on September 03, 2023, 10:46:44 pm

author: shawty
author_rank: Regular Contributor
timestamp: September 03, 2023, 11:12:21 pm
content: Quote from: CountChocula on September 03, 2023, 08:17:06 pmThanks Count!Yea I was going to start at 5v, and in fact that's what I've been testing them with so far. My DC Bench can rock up to 30, so getting 12 not a problem.Never heard of a voltage trimmed oscillator before... seriously :-) I have a boxful of tiny 4 pin ones from 1 Mhz right up to 100 Mhz and they all have exactly the same pinout, even from different manufacturers, I'm used to just going clockwise from upper left -> Ground, Sig, VCC, NCIt's somewhere to start investigating though, that's the main thing. The stuff you find when doing loft clearances is amazing!CheersShawty

author: shawty
author_rank: Regular Contributor
timestamp: October 06, 2023, 11:34:34 am
content: So, I finally got some time to have a play with these things, if you turn them over with the pins facing up and the "3 pins" on the left....They have the same pinout as a normal micro 4 pic oscillator, and they run off of 5 volts.Lower Right (Pin 5) - Ground [Verified with continuity to metal case]Upper Right (Pin 4) - Signal OutputUpper Left (Pin 3) - +v (+5 for now, not tried any higher)The other 2, not tested for anything yet, but on this configuration for most 4 pin ones, pin 1 is usually NC, so assuming that, and assuming that they are VCO's then I suspect Pin 2 is the voltage control, I have however got a signal out of them without connecting anything to pins 1 & 2.Shawty