Submitting An Electronics Design to a Magazine

[Joel Kolstad]

I designed my first analog IC in 1963, the MC1530/31 OpAmp.

Didn't you mention once that the way it was designed, back then, was on a
regular PCB using discrete transistors, resistors, etc. that were built using
the same process the final IC would be using?

I guess that some parasitic inductance and capacitance couldn't have been that
big of a deal, eh?

 

[Don Lancaster]

I designed my first analog IC in 1963, the MC1530/31 OpAmp.

...Jim Thompson

I faked my first analog IC projects because the analog chips were too
expensive.

You could take a uL914 dual logic gate and make a long tailed pair
diffamp out of them. As in the IC67 metal locator.

Even earlier, I took a MECL gate and used it as a linear amp.



--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[[email protected]]

Didn't you mention once that the way it was designed, back then, was on a
regular PCB using discrete transistors, resistors, etc. that were built using
the same process the final IC would be using?

I guess that some parasitic inductance and capacitance couldn't have been that
big of a deal, eh?

Prior to switcap being released, companies would breadboard switched
capacitor filters. Even after switcap was released, I recall one modem
project I was working on where the entire chip was breadboarded. In
this particular design, the DSP and uP were off the shelf items, so we
only designed an analog front end.

Needless to say, we scaled up all the capacitors. I don't even recall
the ratio, but probably a factor of 100.

 

[Jim Thompson]

Didn't you mention once that the way it was designed, back then, was on a
regular PCB using discrete transistors, resistors, etc. that were built using
the same process the final IC would be using?

Actually the MC1530 pre-dates "kit parts". I think I bread-boarded
with 2N2222's.

But the design is all mathematically balanced... see my website for
the analysis.

I guess that some parasitic inductance and capacitance couldn't have been that
big of a deal, eh?

Not for such a design.

...Jim Thompson

 

[Jim Thompson]

I faked my first analog IC projects because the analog chips were too
expensive.

You could take a uL914 dual logic gate and make a long tailed pair
diffamp out of them. As in the IC67 metal locator.

Even earlier, I took a MECL gate and used it as a linear amp.

And there's a MECL diff-pair I made a harmonic mixer out of, and wrote
a paper about.

...Jim Thompson

 

[Rich Grise]

I faked my first analog IC projects because the analog chips were too
expensive.

You could take a uL914 dual logic gate and make a long tailed pair diffamp
out of them. As in the IC67 metal locator.

Even earlier, I took a MECL gate and used it as a linear amp.

Hell, even the most modern of digital stuff is still just analog, driven
to the rails. ;-)

I wonder if it pisses off either camp when they see someone use a(an?)
HCU04 in a mic preamp or something? ;-)

Hey! There's an idea! An FM bug using a(an?) HCU04! ;-)

Cheers!
Rich