looking for an OCXO pinout - Page 1
Forum section: electronics / rf-microwave

author: jujun
author_rank: Regular Contributor
timestamp: December 06, 2018, 08:33:10 pm
content: Hello,I just got a 52Mhz OCXO, that was sold as a Nokia Siemens - V42311-Z70-A1/02.The given pinout dosent match the ground of the case. The pin 3 and 5 are connected to the ground of the enclosure. The pin 1 dosent seems connected at all.So it must be something else.I found on the ndk.com website in the discontinued product similar product, but none match it (or I'am blind).Do you have any advices, before I unsolder the enclosure ?Thank youJulien

author: jujun
author_rank: Regular Contributor
timestamp: December 08, 2018, 05:09:45 pm
content: The metal cover seems hard to remove ...Maybe I can avoid this.I just noticed that there is only one track that is a little wider than others, so I think it's the main positive power.Maybe I should try to put power between this track and the ground of the top cover.Is it a mistake ?

author: Wolfgang
author_rank: Super Contributor
timestamp: January 24, 2019, 10:02:13 pm
content: Why do you know its an OCXO and not just a TCXO ?

author: awallin
author_rank: Frequent Contributor
timestamp: January 25, 2019, 05:39:45 am
content: Quote from: jujun on December 06, 2018, 08:33:10 pmFWIW connor-winfield seems to use that same 7-pad SMD configuration - maybe it's some kind of standard for SMD oscillators?example datasheet (they probably have many many more):http://www.conwin.com/datasheets/cx/cx210.pdf

author: jujun
author_rank: Regular Contributor
timestamp: January 25, 2019, 09:47:17 am
content: Quote from: awallin on January 25, 2019, 05:39:45 amUnfortunately it dosent match the ground connected to the enclosure.Quote from: Wolfgang on January 24, 2019, 10:02:13 pmIt was sold as an OCXO, but you are right, maybe it's only a TCXO.

author: jpb
author_rank: Super Contributor
timestamp: January 25, 2019, 08:18:30 pm
content: Some pins may be not connected, especially if there are Fixed Frequency and Voltage Controlled variants.I had to work out the pin out of an OCXO that I got off ebay recently (new old stock) which had no pin outs or data sheets available.What I did was just use my Fluke 87V to quickly measure the resistance to case value for all the pins.This gave the ground pin (or would be pins in your case) and there were two very high impedance values (15 to 16 Mohms), one which was 418k (the RF/CMOS output) and one that was only 223 ohms which I guessed (correctly) must be the Vcc pin.Having got the Vcc pin and ground I could power it on and then probe the other pins for any RF output (which turned out to be the 418k one - not surprisingly).I was left with two pins - I thought one might be a reference voltage out but it turned out neither were.I just needed to find which was the frequency control voltage so I just tried both - connected the output to a counter and found which pin caused the frequency to vary.Of course you would need to do this at your own risk - I'm not saying there is no danger of damage but it sounds like you have already done some probing to check which are connected to the case and I doubt that the low voltage on the ohms scale will do damage to either the Vc input (if there is one) or the Vcc input.