Trying to understand how to design circuits

Now you'll have to get Jim to autograph your copy of Bob's book. :-) I do wish Barrie Gilbert would write a book. His papers, occasional book chapters, and patents are entirely too short. And it's too bad Robert Widler didn't write an IC design-tricks book. All we have are a few papers and NSC design notes.

--
 Thanks,
    - Win
Reply to
Winfield Hill
Loading thread data ...

*ALL* "new" design is a randam variation from an existing design.

If the design were *all* new, it would have say, no diff pairs, no cascods, no source followers no etc, that is, it could only be an aimless connection of component terminals, and could not possible achieve anything.

If the new design had no random component, it would, by definition, be derivable from existing designs, in which case it couldn't be genuinely new. Random generation is the only way to produce a non derivable result. If it is random then we have no control over it, by definition. Its random. The brain is a Darwinian machine, and that is how it produces "new" designs. Copying, Selection and Randam variation is all there is.

John, you seen to think that there is merit in coming up with something new. Why? The brain can only do this by a random process, so what's superior about generating something by accident? For example, it way harder to copy a complicated arpeggio and play it fast, then to generate new music. Its piss easy to hit some random notes on a piano.

Kevin Aylward snipped-for-privacy@anasoft.co.uk

formatting link
SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design.

Reply to
Kevin Aylward

With all due respect John, I would have to see *proof* that such "new" topologies actually were superior to the well trusted existing ones.

The number of times I have examined "new" circuits that actually achieve no net benefit from an existing circuit are too numerous to mention. There are many convoluted designs that achieve precisely, nothing. Most people fool themselves. It is very hard to be objective about ones own work.

Its very unlikely that anyone can come up, today, with a real useful topology that hasn't already been looked at. Sure, it does happen, but not very often. Too many people have looked at this stuff for way too long.

Don't be daft. If its already invented, it invented. End of story.

I don't. The opportunity for a really new circuit that actually has new value is < 1:1000.

Kevin Aylward snipped-for-privacy@anasoft.co.uk

formatting link
SuperSpice, a very affordable Mixed-Mode Windows Simulator with Schematic Capture, Waveform Display, FFT's and Filter Design.

Reply to
Kevin Aylward
[snip]

Was he ever sober enough to write a book ?:-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
 Click to see the full signature
Reply to
Jim Thompson

Well, they did things that no oscillators that I'm aware of can do. One, for example, oscillates at 800 MHz, has a TC of a few PPM/K, starts instantly - within 1 ns - of an external trigger, then outputs clock edges regularly on schedule with picosecond accuracy. It can be stopped and restarted in 5 ns or so. I know of no "well trusted existing ones" that can do that.

Another is an LC oscillator, asynchronously triggerable in 2 ns and stoppable within one cycle, that has the longterm accuracy and jitter of the best crystal oscillators. I *know* nobody else has ever done this commercially.

Around my place, we do stuff like this all the time, because we believe it's possible.

Maybe nobody shows you the really good ones.

Disagree. New parts allow new things to be tried. uPs, dense FPGAs, screaming ADCs allow architectures to be put on a board that would have been ludicrous 5 years ago. These architectures need circuits.

Well, I guess I'm doing all of them, and for every one I do, you poor drones are stuck with copying and tweaking the other 999.

John

Reply to
John Larkin

All of yours, maybe.

Am I allowed to use resistors? Wires? Or would that make it derivative?

Because it's fun? Because it's profitable? Because it's beautiful?

Because it amuses me.

Damn, what a bleak opinion you have of yourself.

John

Reply to
John Larkin

Yes, of course. Hey, the book probably would have been better when he wasn't. BTW, since we don't have Widler any more, we'd be pleased to see you write a comprehensive IC-design how-to, with ideas and tricks on every other page. Playing second best to a non-existant Widler book isn't bad. :-)

And, it'd be a far better use of your time than trashing me and other anti-Bush folks here on s.e.d. After you pass on, your book will be a grand legacy, whereas your trashing...

--
 Thanks,
    - Win
Reply to
Winfield Hill

I could even write about Widlar so drunk he ended up sleeping sprawled out on Jim Estep's living room floor... much to Jim's wife's horror when she got up the next morning.

Or the time Widlar and Joel Karp got picked up for DUI by the San Jose police... but let go since the brother of one of the COP's worked as a technician for Widlar.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
 Click to see the full signature
Reply to
Jim Thompson

Thats a good point. But how many regulars here admit that.

Well face facts ... the regulars who talk the most spend more time trolling, insulting those who actually understand the subject, then getting down to talk about real electronics. Most of their answers are easily got with a Google search and most times you find better answers using the same method.

Check up some serious analog /design design books, none recommend the Art of Electronics and neither do most engineers I know. But you have a right to an opinion as I/all do.

infinite

Reply to
infinite

I'd vote for a chapter, "Reminisces on drunks, liberals,Attila the Hun, and other things that tickle my fancy" so long as Jim wrote it _after_ finishing the hard-core stuff. :-)

For those who aren't aware of this, Hans Camenzind -- the designer of the

555 -- wrote a book on analog IC design that's available for free download at
formatting link
or can be purchased in print form at Amazon. I vaguely recall that Hans hung out on sci.electronics long ago, but it's been years now since I've seen a post from him.

---Joel

Reply to
Joel Kolstad

Yep. The practical competence allows you to judge the worth of the simulation.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
 Click to see the full signature
Reply to
Jim Thompson

Thanks for that pointer. Ordered...

-- jm

------------------------------------------------------

formatting link
Note: My E-mail address has been altered to avoid spam

------------------------------------------------------

Reply to
John Miles

Or, you could set your political issues aside, and write a killer book on analog ASICs, or whatever suits your fancy - it's clear you have many years of experience at that stuff, why not share it?

Good Luck! Rich

Reply to
Rich Grise

I reckon mathematical analysis is fine once you've mastered a level of practical competence.

How many times have we heard here that it worked in Spice but won't in real ife ?

Graham

Reply to
Pooh Bear

What makes you think there is "a" process? IME it's several subprocesses running in parallel, but there's one thing I think we all agree on:

Real simple; you first decide where you want to get to, then decide how to get there.

Then you need to describe "where you want to get to" and "how to get there" as concisely as needed; but "as concisely as needed" means figuring out where you can and cannot compromise (identifying design criteria). "Criteria" is from the same root as "critical" which here means "what must I do/not do?".

In writing, must you use simple declarative prose, or poetry? Is Standard English the "best" way to express something or would say Haiku work better? Depends; who's your target audience, and what are you trying to get across? Do you want them to "get it" right away or should they think about it a while?

Where are you trying to get to, how many ways do you know of to get there, and how many are you willing to use?

This kind of thinking (analyzing a problem by starting with known solutions) is not designing.

You appear to be confusing design philosophy with pattern matching. Pattern matching is part of designing but not the whole thing.

In the case of a car we start not with four wheels, an engine, and a chassis etc. but with the premise that we want to make it possible to get x number of people and y amount of stuff a given range of distances in a given range of time. Then we explore some possibilities, one of which is an independently-operated machine that carries a few people and a little stuff over pre-existing roads with non-negotiable characteristics. You know about I.C. engines and stuff like that, so you may wind up with something very like a car.

But if "independently-operated" is considered compromisable (not all that "critical" a criterion), then buses and so on enter consideration. If you decide you don't _have_ to use the roadways then trains and planes become design possibilities. If the terrain allows, maybe you draw on your sailing experience and design a land yacht.

Target identification first, then criteria selection, then possibilities. Then maybe some recursion over the criteria...

IME you start at the end ("where you want to get to") then explore as many possible paths as you know about, then pick one that satisfies as many of the design criteria as possible. When (not if) the boss tells you "that won't do", you begin the compromise process. Figuring out which criteria are really critical can be a pain. ;>)

Sometimes it's a matter of personal preference, professional experience, or what your design house is best set up to do. Sometimes these things compete as in you occasionally have to discard "traditional thinking" or be left behind.

Parts-level thinking is usually a matter of designing the blocks or interfacing blocks (would putting a resistor _here_ speed this oscillator up vs. what's the impedance of this transmission line at that frequency?), but that's an experience thing.

OTOH YMMV. ;>)

Mark L. Fergerson

Reply to
Mark Fergerson

Gee Jim, considering the difference in political opinion you two have, I'd think you'd give puckerface (lemonjuice) a little credit on that ;-)

Tim

P.S. Was on vacation a few days. Took AoE with ;)

-- Deep Fryer: a very philosophical monk. Website:

formatting link

Reply to
Tim Williams

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.