Re: gEDA-user: C++ HDL

[John Doty <jpd@xxxxxxxxx>]

On May 15, 2009, at 3:10 PM, Joerg wrote:

> John Doty wrote:
>> On May 15, 2009, at 2:06 PM, Joerg wrote:
>>
>>> John Doty wrote:
>
> [...]
>
>>> I think the BF862 will be around for a long time,
>>
>> So will the 6L6, but few engineers ever have reason to design with  
>> one.
>>
>
> However, those who do make oodles of money. Audio freaks seem to have
> pockets of infinite depths.

Sure, but so what? There's no need to train the average EE to do this  
work.

>
> There's one 6L6 on duty in our living room, inside a Hammond organ.  
> The
> sound is amazing although it could be done class-D these days. But not
> back in 1961.

My bedside radio has a 42 for its output stage, so I've got you beat  
there ;-). 1934 Stromberg-Carlson, just the right sound for a ball game.

> If you need a new 6L6 you can still buy them fresh off the
> belt from places like Sovtek.

Yeah, but try to find a new 42. Fortunately, tubes that survive their  
first few years and aren't stressed too much tend to last a long time.

>
>
>>> else Digikey wouldn't
>>> keep >10k of them in stock most of the time. The six bump BGA (I  
>>> hate
>>> BGAs...) won't ever happen at reasonable cost
>>
>> Doesn't have to be reasonable cost. The Amptek thing everybody uses
>> is $250 apiece, and is too bulky and power hungry for something like
>> an x-ray APD array. If NASA and DARPA ever quit arguing over who
>> should fund XNAV, they have the need, and they have the money. But
>> they're both as bad as Windows users: "We have a common interest so
>> here's what I need you to develop for me for free...".
>>
>
> Looks like a case of Windows-people phobia :-)

Not phobia, just an observation. gEDA was created by *nix people. It  
is maintained by *nix people. It is extended by *nix people. But  
Windows people who wander in here never come to help, to roll up  
their sleeves and contribute. They would be welcome if they did.

>
> Cost may not matter in your business but it does when it comes to  
> telco
> and other markets.

That's one of the reasons IC's are taking over. In the high volume  
markets they're cheaper than bunches of discretes.

> Many people tend to immediately default to "ready to
> go" modules such as Apex amps where gusto is required. Part of my  
> income
> is related to replacing such designs with discretes, with cost savings
> that regularly stun people. Especially controllers and CFOs ...

As IC's continue to increase in power, they'll get there. Also, many  
power devices these days appear to be discretes, but are IC's inside.  
You can't model a "power MOSFET" as a simple discrete, need a  
subcircuit.

>
>
>>> unless there is a huge
>>> consumer app that needs it. Some laser measurement device or  
>>> whatever.
>>>
>>> As for smaller geometry JFETs, those unfortunately do tend to
>>> vanish and
>>> someday we might even read a eulogy on ye olde 2SK3372 :-(
>>
>> The handwriting is on the wall.
>>
>
> Not yet. The -G version is in mass production and Digikey still has  
> tons
> in stock. If it ever goes lalaland it'll become hard to make  
> micropower
> oscillators that can live off fractions of a volt. Chips don't do that
> well down there.

They keep getting better. Especially for micropower low voltage  
cases. And they've been used in such applications in watches for years.

I remember this same argument over tubes. And while the haven't  
exactly gone away (the reheated cup of tea in my hand is proof!) they  
have been sufficiently eclipsed that for the purposes of a university  
professor designing an EE curriculum they may safely be ignored.  
Discrete semiconductors have the same future, but there is less here  
than you think. Future designers will still have to design with  
individual transistors, but they'll mostly fiddle with w, l, and m  
(or whatever equivalent their HDL uses) to get them. Anybody who can  
analyze the consequences of those choices can easily learn to use  
discretes in the rare cases where they will be necessary. But they'll  
be annoyed by the limited choices. ASIC design has spoiled me enough,  
I'm already there.

John Doty              Noqsi Aerospace, Ltd.
http://www.noqsi.com/
jpd@xxxxxxxxx




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