"Mike Engelhardt has parted ways with Analog Devices"

On Fri, 6 Mar 2020 09:22:53 -0000 (UTC), news@rblack01.plus.com wrote:

On Thu, 05 Mar 2020 18:53:02 -0500, Phil Hobbs wrote:

[snip]

I usually use a directive block with a comment in the first line, e.g.

; SIMULATION COMMAND
.tran 1
;.ac blah blah

That way if you right-click on the first line, you don't get the
training-wheels dialogue box for AC, transient, or noise.

Yep. I have been doing similar, but hadn't twigged that the first-line
comment makes the whole mess go away.

The dialogs for V and I sources don't seem to have this problem. The
syntax for PULSE has changed since IV, though, or rather it doesn't have
defaults for any of the parameters, which broke a lot of my old sims.

I've changed a voltage source from, say, sine to pulse, and had the
dialog box params get scrambled, the same problem as switching between
time and frequency simulation. Apparently a smart editor is too dumb
to realize that it's editing the wrong kind of line.

PULSE(0 5 1m) would turn on the source after 1ms, with a default rise
time of 1 ns IIRC, and leave it on forever, which was good enough for a
lot of situations. That no longer works.

Default rise and fall times are wild.

Like many of us, Mike's not especially young, so his passing the torch
isn't unexpected. Is there a reason to suppose that he didn't jump, but
got pushed?

I met him about two years ago, at a seminar he gave. Which, now it looks
likely there won't be any more, I'm very glad I attended. He didn't seem
on the verge of retirement, quite the opposite. My money would be on
corporate meddling, but we'll probably never know.

I found an actual bug in LT Spice that crashed it. I emailed Mike, who
was in Hungary or somewhere, and he sent me a fixed binary in a couple
of hours.





--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

On Fri, 6 Mar 2020 04:44:18 -0800 (PST), Klaus Kragelund
<klauskvik@hotmail.com> wrote:

On Thursday, March 5, 2020 at 10:07:18 PM UTC+1, John Larkin wrote:
On Thu, 05 Mar 2020 12:53:21 -0800, Joerg <news@analogconsultants.com
wrote:

On 2020-03-04 19:19, Rick C wrote:
On Wednesday, March 4, 2020 at 9:55:22 PM UTC-5, Simon S Aysdie
wrote:
"This does not bode well for the future of LTspice now that Mike
Engelhardt has parted ways with Analog Devices."---analog spiceman


https://groups.io/g/LTspice/topic/cloud_over_ltspice/71467233

Time will tell. I don't know how ADI views LTspice. It's a free
tool that likely provides only a minimum return. Maybe they will
find someone else to take it over. Or maybe they will allow it to
continue without much further effort.


"Minimum return"? That sure would be a very short-sighted view and a
major marketing blunder. For me and many other engineers LTSpice is the
core reason why we use rather expensive switcher chips from the former
LTC and now AD.

Exactly. We use LTC parts because the models work.


We do not use and have never used LTC parts. Simply way too expensive

The models from other manufactors also work

Cheers

Klaus

We're in a market where performance sells and time-to-market matters
and parts cost is almost in the noise. A few of the LTC parts are
worth the cost. We made a lot of money off LT1028, and we use a lot of
the LTM regulator bricks so we don't waste time on power supplies.
Some of their serial DACs are nice.

But we use a lot more TI and ADI. I wonder if ADI will adjust the
premium LTC pricing any.









--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Winfield Hill]

jlarkin@highlandsniptechnology.com wrote...

I wonder if ADI will adjust the premium LTC pricing any.

I hope not. It's a specific strategy to make enough profit
on low volumes to create specialized parts that are super-
helpful to engineers working on unique problems. They make
enough $$ to well document their designs. This might all
go away if AD makes big changes.


--
Thanks,
- Win

 

[Rick C]

On Friday, March 6, 2020 at 1:45:13 PM UTC-5, Winfield Hill wrote:

jlarkin@highlandsniptechnology.com wrote...

I wonder if ADI will adjust the premium LTC pricing any.

I hope not. It's a specific strategy to make enough profit
on low volumes to create specialized parts that are super-
helpful to engineers working on unique problems. They make
enough $$ to well document their designs. This might all
go away if AD makes big changes.

Change is inevitable, progress is not.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Bill Sloman]

On Saturday, March 7, 2020 at 2:23:14 AM UTC+11, jla...@highlandsniptechnology.com wrote:

On Fri, 6 Mar 2020 04:44:18 -0800 (PST), Klaus Kragelund
klauskvik@hotmail.com> wrote:

On Thursday, March 5, 2020 at 10:07:18 PM UTC+1, John Larkin wrote:
On Thu, 05 Mar 2020 12:53:21 -0800, Joerg <news@analogconsultants.com
wrote:

On 2020-03-04 19:19, Rick C wrote:
On Wednesday, March 4, 2020 at 9:55:22 PM UTC-5, Simon S Aysdie
wrote:
"This does not bode well for the future of LTspice now that Mike
Engelhardt has parted ways with Analog Devices."---analog spiceman


https://groups.io/g/LTspice/topic/cloud_over_ltspice/71467233

Time will tell. I don't know how ADI views LTspice. It's a free
tool that likely provides only a minimum return. Maybe they will
find someone else to take it over. Or maybe they will allow it to
continue without much further effort.


"Minimum return"? That sure would be a very short-sighted view and a
major marketing blunder. For me and many other engineers LTSpice is the
core reason why we use rather expensive switcher chips from the former
LTC and now AD.

Exactly. We use LTC parts because the models work.


We do not use and have never used LTC parts. Simply way too expensive

The models from other manufactors also work

Cheers

Klaus

We're in a market where performance sells and time-to-market matters
and parts cost is almost in the noise. A few of the LTC parts are
worth the cost. We made a lot of money off LT1028, and we use a lot of
the LTM regulator bricks so we don't waste time on power supplies.
Some of their serial DACs are nice.

But we use a lot more TI and ADI. I wonder if ADI will adjust the
premium LTC pricing any.

Why should they? They sell into exactly same market.

https://au.element14.com/search?st=AD797

The AD797 (which doesn't have the vices that the LT1028 does) sell for about $20.

https://www.digikey.com/product-detail/en/linear-technology-analog-devices/LT1028CS8-PBF/LT1028CS8-PBF-ND/888545

That's about twice what Mouser are asking for the LT1028.

Not altogether surprising. The process Analog Devices uses to manufacture the AD797 is remarkably fancy.

--
Bill Sloman, Sydney

 

[Uwe Bonnes]

Bill Sloman <bill.sloman@ieee.org> wrote:
....

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------

 

[Bill Sloman]

On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:

Bill Sloman <bill.sloman@ieee.org> wrote:
...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that were really fast, high gain parts, and some comment to the effect that it was a 20-stage process, where regular processes were about 12 stages, but it was all from some Analog Devices presentation, and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end analog parts and MEMS parts in-house, rather than relying on foundries, but nothing all tht specific.

--
Bill Sloman, Sydney

--
Bill Sloman, Sydney

 

On Sun, 8 Mar 2020 04:01:13 -0000 (UTC), Przemek Klosowski
<przemek@tux.dot.org> wrote:

On Wed, 04 Mar 2020 19:19:12 -0800, Rick C wrote:

On Wednesday, March 4, 2020 at 9:55:22 PM UTC-5, Simon S Aysdie wrote:
"This does not bode well for the future of LTspice now that Mike
Engelhardt has parted ways with Analog Devices."---analog spiceman


https://groups.io/g/LTspice/topic/cloud_over_ltspice/71467233

Time will tell. I don't know how ADI views LTspice. It's a free tool
that likely provides only a minimum return. Maybe they will find
someone else to take it over. Or maybe they will allow it to continue
without much further effort.

Probably the only real work it requires is to support models for new
parts. I'd be willing to bet that is already handled by the groups who
produce the various parts.

Mike's 2018 interview says that his main job at AD is creating AD part
models in LTSpice

https://www.youtube.com/watch?v=x6TrbD7-IwU

"Intuition is the most important part of engineering."

That's great.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Bill Sloman]

On Sunday, March 8, 2020 at 2:19:06 PM UTC+11, Rick C wrote:

On Saturday, March 7, 2020 at 8:13:49 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that were really fast, high gain parts, and some comment to the effect that it was a 20-stage process, where regular processes were about 12 stages, but it was all from some Analog Devices presentation, and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end analog parts and MEMS parts in-house, rather than relying on foundries, but nothing all that specific.

I would expect that given the equipment doesn't get out of date as fast as the state of the art stuff used for making advanced digital chips.

They might have less of a drive to get the highest possible resolution, and anyway ion implantation can offer you that rather more cheaply than optical techniques anyway - and has been able to do that for ages. It's as slow as a wet week, so you can only have the high resolution at a few critical spots on the device, which is probably all you need for something like the AD797

Analog parts do tend to be less modular than digital parts.

You probably need to think about the state of the relevant art, rather than thinking that making big fast digital chips is the only art that matters.

> So they can continue pounding out the same parts using fully depreciated assets.

That's probably not the way they see it.

--
Bill Sloman, Sydney

 

[Przemek Klosowski]

On Wed, 04 Mar 2020 19:19:12 -0800, Rick C wrote:

On Wednesday, March 4, 2020 at 9:55:22 PM UTC-5, Simon S Aysdie wrote:
"This does not bode well for the future of LTspice now that Mike
Engelhardt has parted ways with Analog Devices."---analog spiceman


https://groups.io/g/LTspice/topic/cloud_over_ltspice/71467233

Time will tell. I don't know how ADI views LTspice. It's a free tool
that likely provides only a minimum return. Maybe they will find
someone else to take it over. Or maybe they will allow it to continue
without much further effort.

Probably the only real work it requires is to support models for new
parts. I'd be willing to bet that is already handled by the groups who
produce the various parts.

Mike's 2018 interview says that his main job at AD is creating AD part
models in LTSpice

https://www.youtube.com/watch?v=x6TrbD7-IwU

His linkedIn profile says he's at AD---does someone has a source quote
for his leaving?

 

[Rick C]

On Saturday, March 7, 2020 at 11:22:27 PM UTC-5, Bill Sloman wrote:

On Sunday, March 8, 2020 at 2:19:06 PM UTC+11, Rick C wrote:
On Saturday, March 7, 2020 at 8:13:49 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that were really fast, high gain parts, and some comment to the effect that it was a 20-stage process, where regular processes were about 12 stages, but it was all from some Analog Devices presentation, and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end analog parts and MEMS parts in-house, rather than relying on foundries, but nothing all that specific.

I would expect that given the equipment doesn't get out of date as fast as the state of the art stuff used for making advanced digital chips.

They might have less of a drive to get the highest possible resolution, and anyway ion implantation can offer you that rather more cheaply than optical techniques anyway - and has been able to do that for ages. It's as slow as a wet week, so you can only have the high resolution at a few critical spots on the device, which is probably all you need for something like the AD797

You haven't said anything about the technology required to make the parts. That's my point. I think continuing to advance analog design doesn't take the same level of investment as it does for digital designs.

Analog parts do tend to be less modular than digital parts.

You probably need to think about the state of the relevant art, rather than thinking that making big fast digital chips is the only art that matters..

How about sticking with what I said rather than what you imagine I said. I never said anything about the worth of design art. I was talking solely about the cost of production. Most analog designs have fundamental limitations in how small they can be due to power handling. It doesn't really matter so much how many transistors you stuff into the innards of a regulator because the area of the chip will be dominated by the power handling components. So not as much incentive to continue to miniaturize.

So they can continue pounding out the same parts using fully depreciated assets.

That's probably not the way they see it.

You mean they buy new fab lines just so they can start the depreciation cycle over again? Even then, the costs of starting a typical lnew analog design is so much less than a digital design that they can afford to have many devices with much lower production volumes.

You really haven't addressed the meat of anything I've mentioned.

Analog designs are cheaper to start and cheaper to produce. So it is more practical to have lots of designs that aren't super high volume which is simply not the case for digital designs that are anywhere at all near state of the art.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Bill Sloman]

On Sunday, March 8, 2020 at 3:24:35 PM UTC+11, jla...@highlandsniptechnology.com wrote:

On Sun, 8 Mar 2020 04:01:13 -0000 (UTC), Przemek Klosowski
przemek@tux.dot.org> wrote:

On Wed, 04 Mar 2020 19:19:12 -0800, Rick C wrote:

On Wednesday, March 4, 2020 at 9:55:22 PM UTC-5, Simon S Aysdie wrote:
"This does not bode well for the future of LTspice now that Mike
Engelhardt has parted ways with Analog Devices."---analog spiceman


https://groups.io/g/LTspice/topic/cloud_over_ltspice/71467233

Time will tell. I don't know how ADI views LTspice. It's a free tool
that likely provides only a minimum return. Maybe they will find
someone else to take it over. Or maybe they will allow it to continue
without much further effort.

Probably the only real work it requires is to support models for new
parts. I'd be willing to bet that is already handled by the groups who
produce the various parts.

Mike's 2018 interview says that his main job at AD is creating AD part
models in LTSpice

https://www.youtube.com/watch?v=x6TrbD7-IwU

"Intuition is the most important part of engineering."

That's great.

It's actually insane, but if intuition is all you've got, you might agree.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Sunday, March 8, 2020 at 3:50:29 PM UTC+11, Rick C wrote:

On Saturday, March 7, 2020 at 11:22:27 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 2:19:06 PM UTC+11, Rick C wrote:
On Saturday, March 7, 2020 at 8:13:49 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that were really fast, high gain parts, and some comment to the effect that it was a 20-stage process, where regular processes were about 12 stages, but it was all from some Analog Devices presentation, and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end analog parts and MEMS parts in-house, rather than relying on foundries, but nothing all that specific.

I would expect that given the equipment doesn't get out of date as fast as the state of the art stuff used for making advanced digital chips.

They might have less of a drive to get the highest possible resolution, and anyway ion implantation can offer you that rather more cheaply than optical techniques - and has been able to do that for ages. It's as slow as a wet week, so you can only have the high resolution at a few critical spots on the device, which is probably all you need for something like the AD797

You haven't said anything about the technology required to make the parts..

I did mention ion-implantation.

That's my point. I think continuing to advance analog design doesn't take the same level of investment as it does for digital designs.

Analog parts do tend to be less modular than digital parts.

You probably need to think about the state of the relevant art, rather than thinking that making big fast digital chips is the only art that matters.

How about sticking with what I said rather than what you imagine I said. I never said anything about the worth of design art. I was talking solely about the cost of production. Most analog designs have fundamental limitations in how small they can be due to power handling.

Some do. Cambridge Intruments sold an electron beam microfabricator to Thompson in the early 1980s.

The acceptance test was to direct write the very narrow gates on three wafers of very high frequency FETs.

Someone looked at the price Thompson CSF was charging for those FETs and those three wafers would have paid the million dollar price of the machine.

It doesn't really matter so much how many transistors you stuff into the innards of a regulator because the area of the chip will be dominated by the power handling components. So not as much incentive to continue to miniaturize.

Regulators aren't what we were talking about. If you need fine-line structures to get local speed, your argument falls flat.

So they can continue pounding out the same parts using fully depreciated assets.

That's probably not the way they see it.

You mean they buy new fab lines just so they can start the depreciation cycle over again?

Incremental development doesn't necessarily involve buying a new fab line.

> Even then, the costs of starting a typical new analog design is so much less than a digital design that they can afford to have many devices with much lower production volumes.

The cost of working out how to get better performance out of a nominally standard analog design can be appreciable - you may be talking about less numerous elements, but you have to be much pickier about how each elements behaves.

> You really haven't addressed the meat of anything I've mentioned.

Not in terms you seem to be willing to think about.

> Analog designs are cheaper to start and cheaper to produce.

They can be. The step up from the LT1028 to the AD797 (which is actually a simpler circuit) may not have been all that cheap.

> So it is more practical to have lots of designs that aren't super high volume which is simply not the case for digital designs that are anywhere at all near state of the art.

The state of the art for digital designs is not inter-changable with the state of the art for analog designs. You've got different constraints and different targets. A fab line optimised to produce high performance analog isn't going to look much like a fab line optimised to produce any of the various flavours of high performance digital parts.

And of course Analog Devices has a separate fab line designed to produce MEMS (micro-electro-mechanical) parts.

--
Bill Sloman, Sydney

--
Bill Sloman, Sydney

 

[Rick C]

On Sunday, March 8, 2020 at 1:06:08 AM UTC-5, Bill Sloman wrote:

On Sunday, March 8, 2020 at 3:50:29 PM UTC+11, Rick C wrote:
On Saturday, March 7, 2020 at 11:22:27 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 2:19:06 PM UTC+11, Rick C wrote:
On Saturday, March 7, 2020 at 8:13:49 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that were really fast, high gain parts, and some comment to the effect that it was a 20-stage process, where regular processes were about 12 stages, but it was all from some Analog Devices presentation, and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end analog parts and MEMS parts in-house, rather than relying on foundries, but nothing all that specific.

I would expect that given the equipment doesn't get out of date as fast as the state of the art stuff used for making advanced digital chips.

They might have less of a drive to get the highest possible resolution, and anyway ion implantation can offer you that rather more cheaply than optical techniques - and has been able to do that for ages. It's as slow as a wet week, so you can only have the high resolution at a few critical spots on the device, which is probably all you need for something like the AD797

You haven't said anything about the technology required to make the parts.

I did mention ion-implantation.

Yes, you mentioned it again, but neither time was relevant to the issue.

That's my point. I think continuing to advance analog design doesn't take the same level of investment as it does for digital designs.

Analog parts do tend to be less modular than digital parts.

You probably need to think about the state of the relevant art, rather than thinking that making big fast digital chips is the only art that matters.

How about sticking with what I said rather than what you imagine I said.. I never said anything about the worth of design art. I was talking solely about the cost of production. Most analog designs have fundamental limitations in how small they can be due to power handling.

Some do. Cambridge Intruments sold an electron beam microfabricator to Thompson in the early 1980s.

The acceptance test was to direct write the very narrow gates on three wafers of very high frequency FETs.

Someone looked at the price Thompson CSF was charging for those FETs and those three wafers would have paid the million dollar price of the machine.

It doesn't really matter so much how many transistors you stuff into the innards of a regulator because the area of the chip will be dominated by the power handling components. So not as much incentive to continue to miniaturize.


Regulators aren't what we were talking about. If you need fine-line structures to get local speed, your argument falls flat.

Not really. What analog production devices are you suggesting have that sort of fine line requirement that digital devices do today?

So they can continue pounding out the same parts using fully depreciated assets.

That's probably not the way they see it.

You mean they buy new fab lines just so they can start the depreciation cycle over again?

Incremental development doesn't necessarily involve buying a new fab line..

Exactly! In the digital domain they have no choice but to build entirely new fab lines every year or two. With the technology required to build analog devices this is not so much the case and nothing remotely like the expense of the digital fab lines is needed.

Even then, the costs of starting a typical new analog design is so much less than a digital design that they can afford to have many devices with much lower production volumes.

The cost of working out how to get better performance out of a nominally standard analog design can be appreciable - you may be talking about less numerous elements, but you have to be much pickier about how each elements behaves.

Which has very little to do with the issue at hand. The bottom line is designing and fabrication costs of analog are much, much lower than today's digital chips.

You really haven't addressed the meat of anything I've mentioned.

Not in terms you seem to be willing to think about.

Not in any meaningful terms. You are just bobbing and weaving without saying anything meaningful.

Analog designs are cheaper to start and cheaper to produce.

They can be. The step up from the LT1028 to the AD797 (which is actually a simpler circuit) may not have been all that cheap.

Yes, I'm sure it was not "all that cheap". But compared to the digital designs today it was a pittance which is my point. Maybe the AD797 is a chip that can only be profitable at higher volumes, I don't know. But most of the analog chips ADI and LT make are not high volume chips but are still profitable because of the lower costs than with many digital devices.

So it is more practical to have lots of designs that aren't super high volume which is simply not the case for digital designs that are anywhere at all near state of the art.

The state of the art for digital designs is not inter-changable with the state of the art for analog designs. You've got different constraints and different targets. A fab line optimised to produce high performance analog isn't going to look much like a fab line optimised to produce any of the various flavours of high performance digital parts.

I never said they were equivalent. I said the costs of maintaining state of the art digital processing requires huge volumes which aren't required for most analog designs.


> And of course Analog Devices has a separate fab line designed to produce MEMS (micro-electro-mechanical) parts.

More red herrings.

Ok, I think we have covered this completely. Continue on your own if you wish. You aren't adding anything to the conversation at this point.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Bill Sloman]

On Sunday, March 8, 2020 at 6:04:31 PM UTC+11, Rick C wrote:

On Sunday, March 8, 2020 at 1:06:08 AM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 3:50:29 PM UTC+11, Rick C wrote:
On Saturday, March 7, 2020 at 11:22:27 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 2:19:06 PM UTC+11, Rick C wrote:
On Saturday, March 7, 2020 at 8:13:49 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that were really fast, high gain parts, and some comment to the effect that it was a 20-stage process, where regular processes were about 12 stages, but it was all from some Analog Devices presentation, and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end analog parts and MEMS parts in-house, rather than relying on foundries, but nothing all that specific.

I would expect that given the equipment doesn't get out of date as fast as the state of the art stuff used for making advanced digital chips..

They might have less of a drive to get the highest possible resolution, and anyway ion implantation can offer you that rather more cheaply than optical techniques - and has been able to do that for ages. It's as slow as a wet week, so you can only have the high resolution at a few critical spots on the device, which is probably all you need for something like the AD797

You haven't said anything about the technology required to make the parts.

I did mention ion-implantation.

Yes, you mentioned it again, but neither time was relevant to the issue.

Which is to say that you couldn't see the relevance.

The AD797 does seem to use high gain fast PNP transistors, and ion implantation does seem to be the way that Analog Devices gets them. It probably wouldn't be the kind of solution that would work for a digital array of millions of identical sets of transistors, but it's fine for this application.

<snip>

--
Bill Sloman, Sydney

 

[Phil Hobbs]

On 2020-03-07 22:19, Rick C wrote:

On Saturday, March 7, 2020 at 8:13:49 PM UTC-5, Bill Sloman wrote:
On Sunday, March 8, 2020 at 10:22:33 AM UTC+11, Uwe Bonnes wrote:
Bill Sloman <bill.sloman@ieee.org> wrote: ...

Not altogether surprising. The process Analog Devices uses to
manufacture the AD797 is remarkably fancy.

Can you shed some light?

Not a lot. I can recall talk of ion-implanted PNP transistors that
were really fast, high gain parts, and some comment to the effect
that it was a 20-stage process, where regular processes were about
12 stages, but it was all from some Analog Devices presentation,
and I haven't been to one for a decade or so.

Googling did reveal that Analog Devices still make their high-end
analog parts and MEMS parts in-house, rather than relying on
foundries, but nothing all tht specific.

I would expect that given the equipment doesn't get out of date as
fast as the state of the art stuff used for making advanced digital
chips. So they can continue pounding out the same parts using fully
depreciated assets.

Analogue CMOS stopped getting better at about the 180-nm node, and was
certainly going into the tank by 65 nm. At that resolution, you can use
single-exposure DUV or excimer litho and regular chrome masks. That
saves a lot of money.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

Przemek Klosowski.... thank you for pointing to that interview on YouTube. I really liked the guys view on what the ltspice program is for which is so that the engineer can get better intuition as to how his circuits work. It is a piece of verification but should not be used is the sole purpose of verifying. I guess I like it because it resonated with my viewpoints about use of such a program

 

[John S]

On 3/9/2020 6:14 AM, bulegoge@columbus.rr.com wrote:

Przemek Klosowski.... thank you for pointing to that interview on YouTube. I really liked the guys view on what the ltspice program is for which is so that the engineer can get better intuition as to how his circuits work. It is a piece of verification but should not be used is the sole purpose of verifying. I guess I like it because it resonated with my viewpoints about use of such a program

+1

 

[John S]

On 3/9/2020 9:55 AM, jlarkin@highlandsniptechnology.com wrote:

On Mon, 9 Mar 2020 04:14:07 -0700 (PDT), bulegoge@columbus.rr.com
wrote:

Przemek Klosowski.... thank you for pointing to that interview on YouTube. I really liked the guys view on what the ltspice program is for which is so that the engineer can get better intuition as to how his circuits work. It is a piece of verification but should not be used is the sole purpose of verifying. I guess I like it because it resonated with my viewpoints about use of such a program

Being an IC guy, he did miss that a little as regards PC boards. I
often use LT Spice as the only process before I go to a PC board, but
then PC boards can be modified a lot easier than linear ICs, and parts
are mostly temperature stable as purchased.

And I design using LT Spice. Once one has some intuition, one can just
throw parts around in the sim and see what happens. That works
surprisingly well. I have several circuits in production that I don't
really understand.

I don't throw parts around. I design first and then see if my design in
LTSpice shows something I overlooked. If it doesn't result in what I
expected, I try to learn why and correct it.

I do much less math than I used to do. I guess rough values and tweak
in LT Spice. Voltage dividers, filters, oscillators this week. So it's
a calculator, too.

Indeed. I do the same. Sometimes it is faster than using a calculator.

It also draws presentable diagrams to include in emails and manuals.
It's a drawing program.

Agreed. I miss Mike.

 

On Mon, 9 Mar 2020 10:17:56 -0500, John S <Sophi.2@invalid.org> wrote:

On 3/9/2020 9:55 AM, jlarkin@highlandsniptechnology.com wrote:
On Mon, 9 Mar 2020 04:14:07 -0700 (PDT), bulegoge@columbus.rr.com
wrote:

Przemek Klosowski.... thank you for pointing to that interview on YouTube. I really liked the guys view on what the ltspice program is for which is so that the engineer can get better intuition as to how his circuits work. It is a piece of verification but should not be used is the sole purpose of verifying. I guess I like it because it resonated with my viewpoints about use of such a program

Being an IC guy, he did miss that a little as regards PC boards. I
often use LT Spice as the only process before I go to a PC board, but
then PC boards can be modified a lot easier than linear ICs, and parts
are mostly temperature stable as purchased.

And I design using LT Spice. Once one has some intuition, one can just
throw parts around in the sim and see what happens. That works
surprisingly well. I have several circuits in production that I don't
really understand.

I don't throw parts around. I design first and then see if my design in
LTSpice shows something I overlooked. If it doesn't result in what I
expected, I try to learn why and correct it.

My 1200 volt 5 MHz Pockels Cell pulser resulted from throwing parts
around. My current LC oscillator is almost as bad. I didn't understand
it until the simulation, and a breadboard, were working. Intuition
guides throwing. You can't design circuits by truly random fiddling
because the solution space is too big.

"Something I overlooked" could be an entirely new concept.

I do much less math than I used to do. I guess rough values and tweak
in LT Spice. Voltage dividers, filters, oscillators this week. So it's
a calculator, too.

Indeed. I do the same. Sometimes it is faster than using a calculator.

Something like a 5-resistor voltage divider or opamp circuit, made
from parts in stock, is way too hard to design on paper.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"