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Products => Test Equipment => Topic started by: dexters_lab on December 06, 2013, 05:16:40 pm

Title: Old HP Logic Analyser Pods
Post by: dexters_lab on December 06, 2013, 05:16:40 pm
I have some pics some of you might be interested in, they are of the probe adaptor from a HP Logic Analyser model 1630G from circa 1985. Originally there was total 8 pods that each provided the interface from the probe clips to the analyser itself.

They proved to be the most interesting thing in it, so thought i'd share.

It's a ceramic pcb, with multiple layers including laser trimmed resistors and several cob devices hidden under a ceramic enclosure.

Title: Re: Old HP Logic Analyser Pods
Post by: dexters_lab on December 06, 2013, 05:18:46 pm
more pics...
Title: Re: Old HP Logic Analyser Pods
Post by: Mark_O on December 07, 2013, 08:01:23 pm
Wow.  That is pretty interesting.  Thanks for the high-rez peeks.
Title: Re: Old HP Logic Analyser Pods
Post by: marshallh on December 07, 2013, 08:35:19 pm
Awesome pics, thanks for sharing
Title: Re: Old HP Logic Analyser Pods
Post by: dexters_lab on December 08, 2013, 08:45:37 am
No worries, figured someone would like to see

Title: Re: Old HP Logic Analyser Pods
Post by: SeanB on December 08, 2013, 08:51:30 am
Front end is a big ASIC and a built in precision power supply for it, voltage reference, opamp and power device all there with some precision trimmed resistors.
Title: Re: Old HP Logic Analyser Pods
Post by: amyk on December 08, 2013, 10:29:40 am
Was it dead?
Title: Re: Old HP Logic Analyser Pods
Post by: dexters_lab on December 08, 2013, 12:12:59 pm
Was it dead?

No, i believe it was working when i bought it

Title: Re: Old HP Logic Analyser Pods
Post by: TiN on December 08, 2013, 04:30:39 pm
Thanks for pics, nice to see such stuff on web.

Here's my Tek P6810 probe tip photo:

(http://fotkidepo.ru/photo/115530/50896lhF73OzqbP/929553w.jpg)
Title: Re: Old HP Logic Analyser Pods
Post by: dexters_lab on December 08, 2013, 04:52:26 pm
Front end is a big ASIC and a built in precision power supply for it, voltage reference, opamp and power device all there with some precision trimmed resistors.

Thanks Sean

Cables from the pod to the analyzer are twisted pairs so guess then asic is also a differential driver?
Title: Re: Old HP Logic Analyser Pods
Post by: dexters_lab on December 08, 2013, 05:11:03 pm
Thanks for pics, nice to see such stuff on web.

Here's my Tek P6810 probe tip photo:

(http://fotkidepo.ru/photo/115530/50896lhF73OzqbP/929553w.jpg)

Lol, you are brave! Just looked at the price of those :o
Title: Re: Old HP Logic Analyser Pods
Post by: codeboy2k on December 09, 2013, 04:50:07 am
Black magic, thy name is HP!

Great pics, thanks for sharing !

If I'm not mistaken, there are some precision trimmed caps on there too.

What kind of process is that, where they seem to screen-print the traces, the resistors and some kind of insulating bridges and also the dielectric for the capacitors?  Does anyone know?

You can see where they built it with the RC network shorted out by fused links, probably used the ATE to first test that it had continuity from the board to the probes, then zapped all the fuses, and trimmed the RC network for each probe tip using some test signals for maximum bandwidth. 

oldskool HP Voodoo Magic, I say :)




Title: Re: Old HP Logic Analyser Pods
Post by: edavid on December 09, 2013, 06:02:28 am
What kind of process is that, where they seem to screen-print the traces, the resistors and some kind of insulating bridges and also the dielectric for the capacitors?  Does anyone know?

It's called a thick film hybrid (http://en.wikipedia.org/wiki/Hybrid_integrated_circuit) (but that Wikipedia article isn't very good, look at some other sources).

It's an old, low tech, but fairly high cost technology.  Even my not very well equipped alma mater had a hybrid lab.
Title: Re: Old HP Logic Analyser Pods
Post by: codeboy2k on December 09, 2013, 07:52:56 am
It's called a thick film hybrid (http://en.wikipedia.org/wiki/Hybrid_integrated_circuit) (but that Wikipedia article isn't very good, look at some other sources).

It's an old, low tech, but fairly high cost technology.  Even my not very well equipped alma mater had a hybrid lab.

Thanks! I'll dig up some more on it to satisfy my curiosity.. My alma mater had a VLSI lab, probably had a hybrid lab too, but I never went down that path and into those labs.  What fun I missed ... ;)

EDIT: found an informative page here:
http://www.ami.ac.uk/courses/topics/0255_tft/ (http://www.ami.ac.uk/courses/topics/0255_tft/)