LTspice, a great program, but that UI!

[rickman]

Every time I want to do something with LTspice I have to fight the UI
something wicked. Doing anything relating to commands is pure torture.

I eventually figured out how to do what I wanted, but it is amazing how
poor not only the UI is, but the documentation. I have learned
programming languages by reading the manuals. But I can't decipher the
.MEAS statement in LTspice along with many other features.

--

Rick C

[M Philbrook]

In article <o9veuf$50c$1...@dont-email.me>, gnu...@gmail.com says...

Please be advised, LTspice and those like it are real programs designed
for serious users in mind looking for real productivity tools for those
that are PRODUCTIVE.

Stop reading the PDF for those game apps.

Jamie

[Kevin Aylward]

"M Philbrook" wrote in message
news:MPG.332f37eee...@news.eternal-september.org...

Pardon?

http://www.anasoft.co.uk/worstcase.htm

LTSpice is a freebee that lacks major key features for productive,
professional use, imo...

Anyone can piss about and make a one off work.

-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html

[John Larkin]

I get a lot of use out of LT Spice. It just took a few minutes to
figure out the basics of entering a schematic and running a transient
analysis. It's much friendlier than some others that I've used (like
EWB) and a lot cheaper too.

It's easy enough to use that I also use it instead of a calculator,
for simple things like voltage dividers and time constants and opamp
resistor calcs. I confess that I've also used it to design LC filters
by pure fiddling. Instinct and simulation can get you a long way.

The HELP could be a lot better. The spotty HELP make it a lot harder
to do some things. There are other resources online, but they take
some digging, and many just repeat one another. One of the best kept
secrets is the space bar.

I suspect that part of the motivation and value of the Analog Devices
purchase of LTC was LT Spice; a couple of billion dollars worth maybe.
I've heard that ADI will be migrating to LT Spice for their parts.

I wish the scissors icon and the run icon looked more different; I
tend to click the wrong one.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

[Jim Thompson]

On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

I think most people who have used, and swear by LTspice have never
used, or even been exposed to, a professional simulation tool.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Thinking outside the box... producing elegant solutions.

[Kevin Aylward]

"Jim Thompson" wrote in message
news:ia4bcc9e1dh1uq7pf...@4ax.com...

On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

>"M Philbrook" wrote in message
>news:MPG.332f37eee...@news.eternal-september.org...
>
>In article <o9veuf$50c$1...@dont-email.me>, gnu...@gmail.com says...
>>
>> Every time I want to do something with LTspice I have to fight the UI
>> something wicked. Doing anything relating to commands is pure torture.
>>
>>> I eventually figured out how to do what I wanted, but it is amazing how
>>> poor not only the UI is, but the documentation. I have learned
>>> programming languages by reading the manuals. But I can't decipher the
>>> .MEAS statement in LTspice along with many other features.
>
>> Please be advised, LTspice and those like it are real programs designed
>>for serious users in mind looking for real productivity tools for those
>>that are PRODUCTIVE.
>
>Pardon?
>
>http://www.anasoft.co.uk/worstcase.htm
>
>LTSpice is a freebee that lacks major key features for productive,
>professional use, imo...
>
>Anyone can piss about and make a one off work.
>

>I think most people who have used, and swear by LTspice have never
>used, or even been exposed to, a professional simulation tool.

I agree. Or actually design ICs that have to work when sold in the millions
per month range.

The reality, is that of the 3,000,000 downloads, the bulk are used by
students and amateurs. By that I mean this.

The bulk of all electronics is IC electronics. That is, billions and
billions of 10,000s of different products, sold every year are integrated
circuits. The number of products with no ICs, is pretty much in the noise.
This ranges from TVs, medical scanners, mobile phones, you name it, it is
IC based.

None of these designs (except maybe Linear Tech :-) ) are taped out using
LTSpice. Its all professional tools, costing real money. Yeah, I am making a
statement without actually have provable numbers, but maybe the one that
does, don't post here to contradict me.

[Kevin Aylward]

"John Larkin" wrote in message
news:pi2bcc1mmrc1027fu...@4ax.com...

On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

>"M Philbrook" wrote in message
>news:MPG.332f37eee...@news.eternal-september.org...
>
>In article <o9veuf$50c$1...@dont-email.me>, gnu...@gmail.com says...
>>
>> Every time I want to do something with LTspice I have to fight the UI
>> something wicked. Doing anything relating to commands is pure torture.
>>
>>> I eventually figured out how to do what I wanted, but it is amazing how
>>> poor not only the UI is, but the documentation. I have learned
>>> programming languages by reading the manuals. But I can't decipher the
>>> .MEAS statement in LTspice along with many other features.
>
>> Please be advised, LTspice and those like it are real programs designed
>>for serious users in mind looking for real productivity tools for those
>>that are PRODUCTIVE.
>
>Pardon?

>I suspect that part of the motivation and value of the Analog Devices
>purchase of LTC was LT Spice; a couple of billion dollars worth maybe.

I have to say, no way josa, and ROTFLMAO. :-)

John. Not a chance in a billion that LTSpice has a business worth even
remotely near that value. Its a freebe, so it would be simply impossible to
justify it as shareholder value as anything more than dubious "goodwill".

*The* fundamental reason companies buy other companies, is to take their
*existing customers*, via the *products* that they *sell*. Its because the
other company is eating into their markets or markets they want to enter.
Its that simple. It has to be hard profit and loss quantifiable motives,
that convince investors and shareholders.

I propose that LTSpice played no part whatsoever in Analog Devices
decision. Lets see if Mike pops up to contradict me.

[Phil Hobbs]

I just set the keyboard shortcut for 'run' to F5, which is familiar from
various C++ IDEs such as Visual Studio.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

[Jim Thompson]

On Sun, 12 Mar 2017 19:39:18 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

>"Jim Thompson" wrote in message
>news:ia4bcc9e1dh1uq7pf...@4ax.com...
>

[snip]

>
>>I think most people who have used, and swear by LTspice have never
>>used, or even been exposed to, a professional simulation tool.
>
>I agree. Or actually design ICs that have to work when sold in the millions
>per month range.
>

[snip]

>
>None of these designs (except maybe Linear Tech :-) ) are taped out using
>LTSpice. Its all professional tools, costing real money. Yeah, I am making a
>statement without actually have provable numbers, but maybe the one that
>does, don't post here to contradict me.
>
>
>
>-- Kevin Aylward
>http://www.anasoft.co.uk - SuperSpice
>http://www.kevinaylward.co.uk/ee/index.html

I really doubt the Linear Tech uses LTspice for design, except,
perhaps, an in-house version as the engine immersed into a Cadence
environment.

[Jim Thompson]

On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward"

>:-}

Observing that Analog Devices simulator is web-based only, "in the
Cloud", I can guess where LTspice is headed >:-}

[John Larkin]

On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward"

LT Spice has sold a lot of LT parts.

[John Larkin]

On Sun, 12 Mar 2017 19:39:18 -0000, "Kevin Aylward"

I don't design ICs, I buy them. I design and sell boards. LT Spice is
a great tool for helping me do that.

[John S]

I agree, John. I never simulate my entire design, just parts of it to
answer my immediate questions. Then I go to the bench.

I bought SuperSpice some years ago and found it almost impossible to use
even with Kevin's help. That is why I now use LTSpice. It is friendly
and just works. By digging a little, its usefulness can be greatly
increased. Also, it seems to be used by many respected professional
engineers on this group.

[Winfield Hill]

John Larkin wrote...

>
> I don't design ICs, I buy them. I design and sell
> boards. LT Spice is a great tool for helping me do that.

I'm a longtime user of Intusoft's SPICE. It has
superior schematic entry and output graphing and
both are more amenable to publishable stuff. I've
played with LTSpice on and off, but the UI sucks
and I'm not impressed with the graphing, except
maybe for super-long plots for SMPS evaluation,
what it was designed for in the first place.


--
Thanks,
- Win

[Jim Thompson]

On 12 Mar 2017 14:30:54 -0700, Winfield Hill

Most of LTspice's won't run on any other simulator... which I consider
to be a very STUPID marketing move.

And it was done quite purposefully... several years ago I noticed that
updates were replacing Berkeley-compliant models with encrypted
versions that run only on LTspice, so I quickly saved all their models
to a separate directory.

So I only use LTspice to verify that my model writings will run there
as well as on Berkeley-compliant simulators... at the insistence of
clients ;-)

As for the UI sucking... sucking a Chandler Heights (*) sized LEMON...
usually the size of soft balls... for those of you unaware of the
Arizona citrus trade.

(*) Two miles to the west of me.

As for IntuSoft's Spice, pretty good simulator engine, but GUI and
post-processing still not up to original-flavor MicroSim PSpice (which
I have used since DOS days with hand-written netlists :-)

[Cursitor Doom]

On Sun, 12 Mar 2017 14:16:22 -0700, John Larkin wrote:

> I don't design ICs, I buy them. I design and sell boards. LT Spice is a
> great tool for helping me do that.

Kev is obviously heavily biased against LT because he views it as a free
and unwelcome alternative to his SS, so his denigratory remarks have to
be seen in that light.

[Jim Thompson]

I take it you've used neither?

[Cursitor Doom]

On Sun, 12 Mar 2017 14:48:34 -0700, Jim Thompson wrote:

> As for IntuSoft's Spice, pretty good simulator engine, but GUI and
> post-processing still not up to original-flavor MicroSim PSpice (which I
> have used since DOS days with hand-written netlists :-)

PSpice is probably the best implementation ever ever ever.

[John Larkin]

On 12 Mar 2017 14:30:54 -0700, Winfield Hill
<hi...@rowland.harvard.edu> wrote:

>John Larkin wrote...
>>
>> I don't design ICs, I buy them. I design and sell
>> boards. LT Spice is a great tool for helping me do that.
>
> I'm a longtime user of Intusoft's SPICE. It has
> superior schematic entry and output graphing and
> both are more amenable to publishable stuff.

I don't publish stuff, I sell stuff; different application. I see
nothing wrong with the schematic entry or the graphing. I can enter
and sim a simple circuit in a couple of minutes. I have sent screen
shots to customers and put them in manuals. They are plenty good
enough.

I've
> played with LTSpice on and off, but the UI sucks
> and I'm not impressed with the graphing, except
> maybe for super-long plots for SMPS evaluation,
> what it was designed for in the first place.

I works fine for me.

[John Larkin]

On Sun, 12 Mar 2017 22:00:02 -0000 (UTC), Cursitor Doom
<cu...@notformail.com> wrote:

Lotsa Spice Snobs here.

[k...@notreal.com]

On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward"

I would suggest that LTSpice gets LT repsonisble for a huge share of
its high margin business. It's the way they support smaller companies
(where the margins are higher). There is no other way to justify
their prices.

[John Larkin]

We had a team of LTC folks visit us last Wednesday, partly to tell us
about the expected effects of the ADI acquisition. They agreed with me
that LT Spice is going to be important to ADI, and that LT Spice has
probably sold gigabucks of parts so far.

Some of their parts are good deals. Not gumdrop opamps or regulators,
but things like fast ADCs and multi-channel serial DACs.

We've used thousands of their LTM micro-brick switchers. Nice quiet
little things.

[k...@notreal.com]

Way too expensive. When we can buy SMPS regulator chips for well less
than $.50 (and add another $.20 for passives), these sorts of things
don't hold the interest much.

[John Larkin]

"Expensive" depends on the context. They are small, convenient, and as
I noted, very quiet. Two inches away from a 250 MHz, 12 bit ADC, I
don't want a lot of switching spikes in my ground plane.

[k...@notreal.com]

On Sun, 12 Mar 2017 19:58:33 -0700, John Larkin

You've just stated my point about LTSpice, and LT in general. Great
stuff, if you're making tens or hundreds a month. Not so great if
you're making thousands or hundreds of thousands. TI doesn't give
much support for people making tens or hundreds but...

It's a matter of market. LTSpice allows LT to go after the high
margin business, where they want to play. TI, for instance, has a
completely different marketing model.

[John Larkin]

If I post a question to one of the TI forums, somebody generally
answers it pretty promptly, and usually fairly well. I actually have
some support contacts at TI, but I think the forums work about as well
in most cases. My question and answer get googl indexed for the rest
of the world to see.

Distributor FAEs work for small companies too.

>
>It's a matter of market. LTSpice allows LT to go after the high
>margin business, where they want to play. TI, for instance, has a
>completely different marketing model.
>

Sure. We average about 20% overall parts cost compared to selling
price. Half of that is PC boards and packaging. So I don't worry much
about parts cost. I do use cheap TI synchronous switchers and external
Ls and Cs when it's reasonable, and when I have a lot of them on a
board.

On a production run of, say, 50 or 100 pieces, it's good to minimize
the number of line items on the BOM. Every part has to be loaded into
feeders and such.

Hey, I use LT Spice for non-LT sims. UniversalOpamp2 is handy.

[Kevin Aylward]

"Cursitor Doom" wrote in message news:oa4gd2$h3o$1...@dont-email.me...

Simply not true. I wrote SS for *ME*. I wrote it after evaluation all
available spices at the time around 1996. Other than, PSpice, they all had
shit GUIs. Any money I get from SS, goes straight to my 80 year old mother,
not me.

I give an accurate, non biased view, as an engineer. Period. Believe what
you want.

I have repeatedly stated that LTSpice, to my knowledge, has the fastest and
best convergence of any PC Spice. However, its GUI, is a joke. Seriously.
For me, its the twilight zone how anyone can find its GUI ok. If the GUI was
usable, I would be using it. I want the best speed and convergence and
features myself. Dah...

LTSpice simply does not have the core features that I *need* and use *every*
day, as a companion to Cadence Virtuoso in my professional IC design work.

http://www.anasoft.co.uk/worstcase.htm

Having to press a menu/function key just to move a component, is just
insane....

[Robert Loos]

May be it looks a little bit home made and uses odd shortcuts but it has
one feature that makes entering schematics as fast as no second program
I know:
There is no need to place wires from pin to pin! Just place a few parts,
then draw a wire right through them and when you end the wire (right
click or escape) all lines that would short a component magically disappear.
Also, if you place a component right over a wire, the piece of wire
under the component is automatically deleted.
Frequently used components like resistors, inductors, diodes or ground
symbols can be inserted without moving the mouse to a menu by typing r,
l, d or g.
Rotate is ctrl-r but mirror is _not_ ctrl-m :-(
Anyhow, very nice imho!

Robert

[Kevin Aylward]

wrote in message news:4t2ccc969i3l4h4o3...@4ax.com...

This claim makes no sense. LTSpice is *only* a *simulation* program. A
simulation program can't "allow" them to sell parts.

LTSpice is, essentially, an advertising tool. It simply puts the name LT on
the desktop. Sure, this has value, but purchasing departments don't buy
parts based on simulating LT chips on a computer, its, does the part meet
the performance required, at a cost I am willing to be, with an acceptable
lead time .

[Kevin Aylward]

"John Larkin" wrote in message

news:covbcc1ephgugsdnj...@4ax.com...

And just what would you expect them to say about LTSpice?

LTSpice, is essentially, advertising. Its not easy to work out the effect of
advertisement on profits, however, one can try different campaigns over time
to see if there is any correlation.

Without supplying LTSpice for a time, then cutting it off over several
periods, I don't see how its possible to validly quantify any value to it
all, although I agree that LTSPice has some value.


"probably sold gigabucks of parts", is just a fantasy claim.


I do remember when Bruce Springteen's "Born In The USA" album came out, it
apparently boosted Levi's jean sales

[Kevin Aylward]

"John Larkin" wrote in message

news:p9ebcct498ug963d9...@4ax.com...

>LT Spice has sold a lot of LT parts.

Maybe, maybe not. How do know? What physical evidence is there of that?

[Kevin Aylward]

"Kevin Aylward" wrote in message
news:mZ-dnWN2AsZz11vF...@giganews.com...

>"Cursitor Doom" wrote in message news:oa4gd2$h3o$1...@dont-email.me...

>On Sun, 12 Mar 2017 14:16:22 -0700, John Larkin wrote:

>> I don't design ICs, I buy them. I design and sell boards. LT Spice is a
>> great tool for helping me do that.

>>Kev is obviously heavily biased against LT because he views it as a free
>>and unwelcome alternative to his SS, so his denigratory remarks have to
>>be seen in that light.

>Simply not true.

I will expand on that, in part this will give a bit of general knowledge as
to what "pro ic design is all about" that readers here may find useful.

Key parameters in producing a commercial IC product are.

1 It takes several months to get a design back from the fab after tapeout.
2 ICs, typically today, are complicated, 10,000s of transistors for an
analog ASIC
3 A 0.18u process might take $100k in prototype fab costs
4 Fab process have extensive variations
5 Millions sold per month must work, reliably, for many years.

So, prior to tapeout, an ic designs are required to have extensive design
effort and verification.

The process of designing, say a BiCMOS chip, involves going through a range
of design optimisations and simulations. This consists of designing for DC,
AC TRAN, NOISE, in an iterative manner.

The details of the design involve selecting, for example, gate lengths and
widths, and how many in parallel and series, and emitter areas. For example,
shorter gate lengths get you faster speed. Maximising headroom may be
achieved by reducing the Vdsat of the transistor, by reducing its overdrive
voltage, Vgst (Vgs-Vth), this means say, increasing the ratio of W/L.
However, reducing Vgst, makes matching worse, so compromises have to be
made. Better matching means larger W x L, however, this means a slower
circuit, which could mean instability in a feedback loop. etc...etc... all
to satisfy specifications of power consumption, noise, die size,
etc...etc...

Now, all of this has to be done with process variations, say Vt varying by
200mv, gm of mosfet varing 20%, and over temperatures, say -40 deg to 85deg,
over all supply voltages. Typically models are made that reflect the
extremes of the process, which I explain in more detail here:

http://www.anasoft.co.uk/worstcase.htm

Typically, 100,000s of simulations are run to verify a chip before tapeout.

So, no, I do not have "bias". My view is based on the facts.

If a simulator does not directly support worst case analyses, its dead in
the water as far as IC design in concerned. Period.

Second, is usability of accessing key data that supports the above design
issues. IC design requires spending hours per day, every day, running
continually modified simulations. Pissing about for a minute to access each
plot *is* a major problem, for serious, professional designers.

For example, in checking that Vds (drain voltage) is greater than Vdsat
(when device crushes) over *all* process corners, and over the operating DC
ranges, one needs to be able to do this *easily*.

http://www.anasoft.co.uk/screenshots.htm

Scroll down to the second screen shot.

This shows a signal list tab to the left where you can ctrl-click and easily
display a combination of any signal. For example, plotting Vgs and Vdsat.
SuperSpice lists in that signal list all major device parameters such as
Vgst, gm, gds, etc... You don't have to hunt about to get the data that you
really need to plot.

Even small details can have a *major* effect on usability when your
simulating 40 hours per week. For example, SS displays the actual x, y trace
data of the graph without cursors, because the mouse cursor *locks* onto the
trace, and only displays only the *valid* y with x data. LTSpice just
displays apparent x,y data of whether the mouse is on the screen, which has
nothing to do with the real trace data. Using LT manual cursers is a major
pain.

So, sure, if your not an IC design pro, the LT GUI, may well be adequate for
your needs.

[rickman]

I've been through the documentation many times and not all of these
keystrokes were made apparent to me. Yes, somewhere there is a list of
all the hotkeys, but mostly they are control keys and weeding through
the list for the few useful ones is not so easy.

I changed one of the hot keys in the settings so cntl-z was undo as is
the case in so many windows programs. It was promptly forgotten...

I seem to recall fixing some of the waveform colors so they stood out on
a laptop LCD screen... all gone.

If you use the program every day, it can become very familiar. If not,
the arcane little idiosyncrasies get on your nerves. Why doesn't
cntl-A select all the text in a text field??? There's a million things
like this that the few nice features don't make up for.

--

Rick C

[Kevin Aylward]

"Robert Loos" wrote in message news:vbuhpd-...@baer-gmbh.com...

>May be it looks a little bit home made and uses odd shortcuts but it has
>one feature that makes entering schematics as fast as no second program I
>know:
>There is no need to place wires from pin to pin! Just place a few parts,
>then draw a wire right through them and when you end the wire (right click
>or escape)

I just tried that, and it went and connected up incorrectly.
Ahmmm...probably because I am unable to use LTpPice.

>all lines that would short a component magically disappear.
>Also, if you place a component right over a wire, the piece of wire under
>the component is automatically deleted.

It didn't used to do that. Mike copied that from me :-)

But in reality, I hardly ever use that feature

>Frequently used components like resistors, inductors, diodes or ground
>symbols can be inserted without moving the mouse to a menu by typing r, l,
>d or g.

So, you don't see the value in having docked, tabbed sidebars that you can
drag any of the component form any library?

http://www.anasoft.co.uk/screenshots.htm

To add model libraries, you just drag drop the file from explorer. Symbols
for standard models are attached automatically.

>Rotate is ctrl-r but mirror is _not_ ctrl-m :-(

There is no rational reason to have the ctrl key as well, SS don't do that,
its just "r" "m" "f" to rotate, mirror flip up/down. Zoom in/out is "i" "o"

Double-clicking on component does what you expect in windows, as does right
click popping up a menu :-)

[bule...@columbus.rr.com]

Great post on a great thread.

[Kevin Aylward]

>"Cursitor Doom" wrote in message news:oa4h2j$h3o$1...@dont-email.me...

Always reminds me of:

Bodacious cowboys
Such as your friend
Will never be welcome here
High in the Custerdome

Steely Dan - Gaucho

PSpice was very good. Where do you think I stole the idea for moving around
testpoints on the schematic?

I used PSpice from around 1985 to 1997, whilst I was a board level designer,
paid for at the various companies I worked at. I commenced the SS project as
I was poor and could not afford £2,500. So, it was 4 years of weekend and
night time work and 150,000 lines of code...

I checked out IntuSoft during that period, and rejected it immediately I
discovered that you had to put 0V voltage sources in leads to plot currents.
A total no, no. Pspice has .probe, you get everything.

I checked out ALL the spices at the time, none were usable. That's *why* I
wrote SS. I needed a usable Spice, personally.

When I got the Berkeley Spice3/XSpice code, around 1997, I discovered that
the BSim3 model code did not actually provide terminal currents for the
gate, drain and bulk. So, my first task was to spend a week or so, trial and
erroring adding up the various terms in the data structures to get the total
current from all the individual bits. The issue being, is that its a no
documentation, student written bunch of spaghetti.

[John Larkin]

On Mon, 13 Mar 2017 08:42:25 -0000, "Kevin Aylward"

The fact that it is available for download, free. And the fact that
other semi makers are offering similar free simulators for their
parts.

And because the LTC people physically told me so last week.

[John Larkin]

On Mon, 13 Mar 2017 08:33:47 -0000, "Kevin Aylward"

Purchasing departments buy what engineers put on the BOM. If the part
is sole-source, they have no choice.

In most cases, an engineer can even declare an LM317 to be
sole-source. Much less an LTC2242.

My purchasing dept is not allowed to overrule an engineering decision
and buy whatever they want. Heaven help companies where they are.

I know lots of engineers who pull a part off the LT Spice parts menu,
sim their circuit, and design in the LTC part.

LTC just sold to ADI for $12 billion, about 10x annual sales. That's
pretty good.

[Jim Thompson]

On Mon, 13 Mar 2017 08:29:22 +0100, Robert Loos <12...@baer-gmbh.com>
wrote:

>May be it looks a little bit home made and uses odd shortcuts but it has
>one feature that makes entering schematics as fast as no second program
>I know:

[snip]
>
>Robert

Monumental BS.

I invite anyone who thinks that the LTspice GUI is "as fast as no
second program I know" to drop by, if you're in the East Valley area
of the Phoenix 'burbs, and see a demonstration of a real schematic
capture.

Bring your laptop.

At that time we'll locate a mutually acceptable schematic image off
the web, you can enter it in LTspice, I'll enter with MicroSim PSpice
Schematics... you'll get your ass whipped >:-}

[John Larkin]

On Sun, 12 Mar 2017 16:29:11 -0500, John S <Sop...@invalid.org>
wrote:

>On 3/12/2017 4:16 PM, John Larkin wrote:
>> On Sun, 12 Mar 2017 19:39:18 -0000, "Kevin Aylward"
>> <kevinR...@kevinaylward.co.uk> wrote:
>>
>>> "Jim Thompson" wrote in message
>>> news:ia4bcc9e1dh1uq7pf...@4ax.com...

>>>
>>> On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward"
>>> <kevinR...@kevinaylward.co.uk> wrote:
>>>
>>>> "M Philbrook" wrote in message
>>>> news:MPG.332f37eee...@news.eternal-september.org...
>>>>
>>>> In article <o9veuf$50c$1...@dont-email.me>, gnu...@gmail.com says...
>>>>>
>>>>> Every time I want to do something with LTspice I have to fight the UI
>>>>> something wicked. Doing anything relating to commands is pure torture.
>>>>>
>>>>>> I eventually figured out how to do what I wanted, but it is amazing how
>>>>>> poor not only the UI is, but the documentation. I have learned
>>>>>> programming languages by reading the manuals. But I can't decipher the
>>>>>> .MEAS statement in LTspice along with many other features.
>>>>
>>>>> Please be advised, LTspice and those like it are real programs designed
>>>>> for serious users in mind looking for real productivity tools for those
>>>>> that are PRODUCTIVE.
>>>>
>>>> Pardon?
>>>>

>>>> http://www.anasoft.co.uk/worstcase.htm
>>>>
>>>> LTSpice is a freebee that lacks major key features for productive,
>>>> professional use, imo...
>>>>
>>>> Anyone can piss about and make a one off work.
>>>>
>>>
>>>> I think most people who have used, and swear by LTspice have never
>>>> used, or even been exposed to, a professional simulation tool.
>>>
>>> I agree. Or actually design ICs that have to work when sold in the millions
>>> per month range.
>>>
>>> The reality, is that of the 3,000,000 downloads, the bulk are used by
>>> students and amateurs. By that I mean this.
>>>
>>> The bulk of all electronics is IC electronics. That is, billions and
>>> billions of 10,000s of different products, sold every year are integrated
>>> circuits. The number of products with no ICs, is pretty much in the noise.
>>> This ranges from TVs, medical scanners, mobile phones, you name it, it is
>>> IC based.
>>>
>>> None of these designs (except maybe Linear Tech :-) ) are taped out using
>>> LTSpice. Its all professional tools, costing real money. Yeah, I am making a
>>> statement without actually have provable numbers, but maybe the one that
>>> does, don't post here to contradict me.

>>>
>>>
>>>
>>> -- Kevin Aylward
>>> http://www.anasoft.co.uk - SuperSpice
>>> http://www.kevinaylward.co.uk/ee/index.html
>>
>>

>> I don't design ICs, I buy them. I design and sell boards. LT Spice is
>> a great tool for helping me do that.
>

>I agree, John. I never simulate my entire design, just parts of it to
>answer my immediate questions. Then I go to the bench.

Right. I only sim or breadboard little snippets of circuit that I have
any doubt about; for most designs, that is none. The best prototype is
the first production unit.

--

John Larkin Highland Technology, Inc

picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

[Kevin Aylward]

"John Larkin" wrote in message

news:65bdcctmdjne57af6...@4ax.com...

Let me clarify,

For engineers, its, does the part meet the performance required, at a cost
the company is willing to pay, with an acceptable lead time.

If an engineer does not design in parts based on that basis, he is not an
engineer.

>LTC just sold to ADI for $12 billion, about 10x annual sales. That's
>pretty good.

That is pretty good for LT. For product designers, its bad news.

Kevin Aylward
ke...@kevinaylward.co.uk
www.kevinaylward.co.uk

[Kevin Aylward]

"John Larkin" wrote in message

news:80bdcclpctdk8lage...@4ax.com...

>>>
>>>Pardon?
>>
>>>I suspect that part of the motivation and value of the Analog Devices
>>>purchase of LTC was LT Spice; a couple of billion dollars worth maybe.
>>
>>I have to say, no way josa, and ROTFLMAO. :-)
>>
>>John. Not a chance in a billion that LTSpice has a business worth even
>>remotely near that value. Its a freebe, so it would be simply impossible
>>to
>>justify it as shareholder value as anything more than dubious "goodwill".
>>
>>*The* fundamental reason companies buy other companies, is to take their
>>*existing customers*, via the *products* that they *sell*. Its because the
>>other company is eating into their markets or markets they want to enter.
>>Its that simple. It has to be hard profit and loss quantifiable motives,
>>that convince investors and shareholders.
>>
>>I propose that LTSpice played no part whatsoever in Analog Devices
>>decision. Lets see if Mike pops up to contradict me.
>>
>>
>
>
>>LT Spice has sold a lot of LT parts.
>
>Maybe, maybe not. How do know? What physical evidence is there of that?
>
>

>The fact that it is available for download, free. And the fact that
>other semi makers are offering similar free simulators for their
>parts.

None of that is *evidence* that providing simulators sells any parts at all,
let alone, lots of parts. Its quite likely that it will improve sales a tad,
but just how much is guesswork.

>And because the LTC people physically told me so last week.

That is some evidence, in the legal sense, but without numbers, and reasons
for the numbers, it don't mean what they said was accurate or even the
truth. As I noted, what would you expect them to say. "LTSpice is a total
loss to us".

When I was designing board level stuff, I would evaluate pretty every single
semiconductor company for the equivalent part I was planning to design in.
Its part of the process of being an engineer. You are going to try and get
the best compromise of performance, cost and availability. It would be just
insane to design in a part just because that was in the kit of your freebe
sim tool. Like, you aren't going to check out any alternatives? This is the
real world. I don't believe any competent engineer would do such a daft
thing.

So, no, I don't believe that LTSpice makes much of a difference in sales.

[John S]

Maybe, maybe not. How do you know? What physical evidence is there of
that? Your opinion is no better than John's.

[John S]

On 3/13/2017 12:00 PM, Jim Thompson wrote:
> On Mon, 13 Mar 2017 08:29:22 +0100, Robert Loos <12...@baer-gmbh.com>
> wrote:
>
>> May be it looks a little bit home made and uses odd shortcuts but it has
>> one feature that makes entering schematics as fast as no second program
>> I know:
> [snip]
>>
>> Robert
>
> Monumental BS.

Considering his statement, your reply is a bit lacking in logic, isn't
it Jim?

He gave no indication that he knows MicroSim PSpice, so his statement is
not necessarily "Monumental BS".

[John Larkin]

Engineering is expensive. Risk can be expensive. Performance can be
valuable. Getting a product to market matters. There's more to
engineering than minimizing the BOM cost.

https://dl.dropboxusercontent.com/u/53724080/PCBs/TEM2_Power_Board.JPG

>
>So, no, I don't believe that LTSpice makes much of a difference in sales.

There wouldn't be a tad of jealousy there, huh?

--

John Larkin Highland Technology, Inc

[John Larkin]

On Mon, 13 Mar 2017 17:17:58 -0000, "Kevin Aylward"

I get to decide what the company is willing to pay, so that simplifies
the process some.

But not many purchasing departments are going to challenge an engineer
on his design choices.

>
>If an engineer does not design in parts based on that basis, he is not an
>engineer.

We seem to have different definitions of "engineer."

Part of what I do is amuse myself and learn things. Sometimes I do
things new ways, or use new parts, for other reasons than piece price.

--

John Larkin Highland Technology, Inc

[John Larkin]

On Mon, 13 Mar 2017 10:00:24 -0700, Jim Thompson
<To-Email-Use-Th...@On-My-Web-Site.com> wrote:

>On Mon, 13 Mar 2017 08:29:22 +0100, Robert Loos <12...@baer-gmbh.com>
>wrote:
>
>>May be it looks a little bit home made and uses odd shortcuts but it has
>>one feature that makes entering schematics as fast as no second program
>>I know:
>[snip]
>>
>>Robert
>
>Monumental BS.
>
>I invite anyone who thinks that the LTspice GUI is "as fast as no
>second program I know" to drop by, if you're in the East Valley area
>of the Phoenix 'burbs, and see a demonstration of a real schematic
>capture.
>
>Bring your laptop.
>
>At that time we'll locate a mutually acceptable schematic image off
>the web, you can enter it in LTspice, I'll enter with MicroSim PSpice
>Schematics... you'll get your ass whipped >:-}
>
> ...Jim Thompson

Challenge them to a drag race too. And a fist fight.

But not a cook-off. You'd lose that one.

[John Devereux]

It depends entirely on the expected production volumes doesn't it? There
are also a lot of unique / niche parts.


--

John Devereux

[Kevin Aylward]

>"John Larkin" wrote in message

>news:66sdccpjrn4sgm0do...@4ax.com...

>
>>And because the LTC people physically told me so last week.
>
>>That is some evidence, in the legal sense, but without numbers, and
>>reasons
>>for the numbers, it don't mean what they said was accurate or even the
>>truth. As I noted, what would you expect them to say. "LTSpice is a total
>>loss to us".
>
>>When I was designing board level stuff, I would evaluate pretty every
>>single
>>semiconductor company for the equivalent part I was planning to design in.
>>Its part of the process of being an engineer. You are going to try and get
>>the best compromise of performance, cost and availability. It would be
>>just
>>insane to design in a part just because that was in the kit of your freebe
>>sim tool. Like, you aren't going to check out any alternatives? This is
>>the
>>real world. I don't believe any competent engineer would do such a daft
>thing.

>Engineering is expensive. Risk can be expensive. Performance can be
>valuable. Getting a product to market matters. There's more to
>engineering than minimizing the BOM cost.

Sure, but one needs to step back a bit here, and examine reality.

Are you really claiming that a competent engineer is not even going to
spend 30 mins on the web. Like *30 min* out of months of development costs,
simply to check out if another suitable part might even exist?

>So, no, I don't believe that LTSpice makes much of a difference in sales.

>There wouldn't be a tad of jealousy there, huh?

No. I have given a lot of thought to what is the value of freebee stuff like
this, and it is not a lot, imo. The reality is, and taking into account your
valid comment in principle of minimising development time, its simple not a
rational way to develop products to not do even the most minimal check of
alternative parts. Its even usually a requirement to design, whenever
possible, a product where you can second source parts.

So, no I don't believe that a competent engineer, using LTSice, will refuse
to even go on the web for *5 minutes* to check if something else is
available. Its utter nonsense to suggest that this wouldn't happen. So,
LTSpice cannot possibly be a genuine *cause* to buy an LT part. The LT part
will be compared to another part, and the then optimum chosen, and it wont
matter whether LTSpice is there or not.

This is how advertising works.

The fundamental point of advertisement is to let the customer know that you
actually exist. Period.

In 1985, if MicroSim did not advertise in magazines, no one would know about
it.
if Intusoft did not advertise in magazines, no one would know about it.

Once engineers know about them, they *WILL* technically evaluate *which* one
suits them best. They don't go, oh, ok, I'll just take the first one I find.
This is not selling perfume.

Today, we have Google. We can all discover TI, Analog Devices and LT, so
the value of freebees, today, has been greatly diminished.

An engineering product is designed based on technical, objective
considerations. Not even spending 5 bloody minutes looking for an
alternative via Google is fantasy. I don't believe for a second that any
engineer does this. Once alternatives are discovered, an engineer will
evaluate them to see if they are a better option.

[Kevin Aylward]

>"John Devereux" wrote in message news:87pohlf...@devereux.me.uk...

>>The fact that it is available for download, free. And the fact that
>>other semi makers are offering similar free simulators for their
>>parts.
>
> None of that is *evidence* that providing simulators sells any parts
> at all, let alone, lots of parts. Its quite likely that it will
> improve sales a tad, but just how much is guesswork.
>
>>And because the LTC people physically told me so last week.
>
> That is some evidence, in the legal sense, but without numbers, and
> reasons for the numbers, it don't mean what they said was accurate or
> even the truth. As I noted, what would you expect them to
> say. "LTSpice is a total loss to us".
>
> When I was designing board level stuff, I would evaluate pretty every
> single semiconductor company for the equivalent part I was planning to
> design in. Its part of the process of being an engineer. You are going
> to try and get the best compromise of performance, cost and
> availability. It would be just insane to design in a part just because
> that was in the kit of your freebe sim tool. Like, you aren't going to
> check out any alternatives? This is the real world. I don't believe
> any competent engineer would do such a daft thing.

>It depends entirely on the expected production volumes doesn't it? There
>are also a lot of unique / niche parts.

Sure, but if it was unique to LT, then they would buy it because its unique
to LT, LTSpice wouldn't matter .

[Jasen Betts]

On 2017-03-13, Kevin Aylward <kevinR...@kevinaylward.co.uk> wrote:
> "John Larkin" wrote in message
> news:80bdcclpctdk8lage...@4ax.com...
>

> None of that is *evidence* that providing simulators sells any parts at all,
> let alone, lots of parts. Its quite likely that it will improve sales a tad,
> but just how much is guesswork.

For us it is guesswork, a statistician with the capability to perfom
experiments and see detailed figures would be able to put a number on it.
said number would then be a trade secret.

--
This email has not been checked by half-arsed antivirus software

[Kevin Aylward]

"Jasen Betts" wrote in message news:oa6rqu$ut$1...@gonzo.alcatraz...

On 2017-03-13, Kevin Aylward <kevinR...@kevinaylward.co.uk> wrote:
> "John Larkin" wrote in message
> news:80bdcclpctdk8lage...@4ax.com...
>

>> None of that is *evidence* that providing simulators sells any parts at
>> all,
>> let alone, lots of parts. Its quite likely that it will improve sales a
>> tad,
>> but just how much is guesswork.

>For us it is guesswork, a statistician with the capability to perfom
>experiments and see detailed figures would be able to put a number on it.
>said number would then be a trade secret.

For LTSpice to be of value to LT, it only has to generate a tad more than
Mike's salary, lets guess that at $500k p.a :-)

[John Devereux]

Yes that is something of a side issue although for most of the "unique"
parts can be implemented with something else but may be more complicated
to design. But for specialist applications where volumes are lower I can
see the attraction of being able to drop in circuit block and have it
"just work", and furthermore be able to immediately demonstrate and
verify that with LTSpice.

Then if volumes of a high profit margin design do take off I can see it
being a while before a tried and trusted, yet relatively expensive part
is designed out.





--

John Devereux

[k...@notreal.com]

On Sun, 12 Mar 2017 21:47:42 -0700, John Larkin
<jjla...@highlandtechnology.com> wrote:

>On Sun, 12 Mar 2017 23:05:33 -0400, k...@notreal.com wrote:
>
>>On Sun, 12 Mar 2017 19:58:33 -0700, John Larkin
>><jjla...@highlandtechnology.com> wrote:
>>
>>>On Sun, 12 Mar 2017 22:46:37 -0400, k...@notreal.com wrote:
>>>
>>>>On Sun, 12 Mar 2017 19:20:41 -0700, John Larkin
>>>><jjla...@highlandtechnology.com> wrote:
>>>>
>>>>>On Sun, 12 Mar 2017 20:15:18 -0400, k...@notreal.com wrote:
>>>>>

>>>>>>On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward"

>>>>>><kevinR...@kevinaylward.co.uk> wrote:
>>>>>>
>>>>>>>"John Larkin" wrote in message

>>>>>>>news:pi2bcc1mmrc1027fu...@4ax.com...
>>>>>>>
>>>>>>>On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward"
>>>>>>><kevinR...@kevinaylward.co.uk> wrote:
>>>>>>>
>>>>>>>>"M Philbrook" wrote in message
>>>>>>>>news:MPG.332f37eee...@news.eternal-september.org...
>>>>>>>>
>>>>>>>>In article <o9veuf$50c$1...@dont-email.me>, gnu...@gmail.com says...
>>>>>>>>>
>>>>>>>>> Every time I want to do something with LTspice I have to fight the UI
>>>>>>>>> something wicked. Doing anything relating to commands is pure torture.
>>>>>>>>>
>>>>>>>>>> I eventually figured out how to do what I wanted, but it is amazing how
>>>>>>>>>> poor not only the UI is, but the documentation. I have learned
>>>>>>>>>> programming languages by reading the manuals. But I can't decipher the
>>>>>>>>>> .MEAS statement in LTspice along with many other features.
>>>>>>>>
>>>>>>>>> Please be advised, LTspice and those like it are real programs designed
>>>>>>>>>for serious users in mind looking for real productivity tools for those
>>>>>>>>>that are PRODUCTIVE.
>>>>>>>>

>>>>>>>>Pardon?
>>>>>>>
>>>>>>>>I suspect that part of the motivation and value of the Analog Devices
>>>>>>>>purchase of LTC was LT Spice; a couple of billion dollars worth maybe.
>>>>>>>
>>>>>>>I have to say, no way josa, and ROTFLMAO. :-)
>>>>>>>
>>>>>>>John. Not a chance in a billion that LTSpice has a business worth even
>>>>>>>remotely near that value. Its a freebe, so it would be simply impossible to
>>>>>>>justify it as shareholder value as anything more than dubious "goodwill".
>>>>>>>
>>>>>>>*The* fundamental reason companies buy other companies, is to take their
>>>>>>>*existing customers*, via the *products* that they *sell*. Its because the
>>>>>>>other company is eating into their markets or markets they want to enter.
>>>>>>>Its that simple. It has to be hard profit and loss quantifiable motives,
>>>>>>>that convince investors and shareholders.
>>>>>>>
>>>>>>>I propose that LTSpice played no part whatsoever in Analog Devices
>>>>>>>decision. Lets see if Mike pops up to contradict me.
>>>>>>

>>>>>>I would suggest that LTSpice gets LT repsonisble for a huge share of
>>>>>>its high margin business. It's the way they support smaller companies
>>>>>>(where the margins are higher). There is no other way to justify
>>>>>>their prices.
>>>>>
>>>>>We had a team of LTC folks visit us last Wednesday, partly to tell us
>>>>>about the expected effects of the ADI acquisition. They agreed with me
>>>>>that LT Spice is going to be important to ADI, and that LT Spice has
>>>>>probably sold gigabucks of parts so far.
>>>>>
>>>>>Some of their parts are good deals. Not gumdrop opamps or regulators,
>>>>>but things like fast ADCs and multi-channel serial DACs.
>>>>>
>>>>>We've used thousands of their LTM micro-brick switchers. Nice quiet
>>>>>little things.
>>>>
>>>>Way too expensive. When we can buy SMPS regulator chips for well less
>>>>than $.50 (and add another $.20 for passives), these sorts of things
>>>>don't hold the interest much.
>>>
>>>"Expensive" depends on the context. They are small, convenient, and as
>>>I noted, very quiet. Two inches away from a 250 MHz, 12 bit ADC, I
>>>don't want a lot of switching spikes in my ground plane.
>>
>>You've just stated my point about LTSpice, and LT in general. Great
>>stuff, if you're making tens or hundreds a month. Not so great if
>>you're making thousands or hundreds of thousands. TI doesn't give
>>much support for people making tens or hundreds but...
>

>If I post a question to one of the TI forums, somebody generally
>answers it pretty promptly, and usually fairly well. I actually have
>some support contacts at TI, but I think the forums work about as well
>in most cases. My question and answer get googl indexed for the rest
>of the world to see.
>
>Distributor FAEs work for small companies too.

But you don't have four people dedicated to your business, one of whom
is an excellent power supply designer. Do they come into Highland and
teach an eight week power design course? ...and bring lunch? ;-)

>>
>>It's a matter of market. LTSpice allows LT to go after the high

>>margin business, where they want to play. TI, for instance, has a
>>completely different marketing model.
>>
>
>Sure. We average about 20% overall parts cost compared to selling
>price. Half of that is PC boards and packaging. So I don't worry much
>about parts cost. I do use cheap TI synchronous switchers and external
>Ls and Cs when it's reasonable, and when I have a lot of them on a
>board.

Yes, that's *many* times our margin. A buck matters.

>On a production run of, say, 50 or 100 pieces, it's good to minimize
>the number of line items on the BOM. Every part has to be loaded into
>feeders and such.

Sure. The nuber of feeders is never a concern for our production (it
is for our CM but I never make it under their limit). The number of
devices matters, of course, because it costs more to place a part than
most parts cost.

>Hey, I use LT Spice for non-LT sims. UniversalOpamp2 is handy.

;-)

My favorite part is "ideal opamp".

[k...@notreal.com]

On Mon, 13 Mar 2017 08:33:47 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

>wrote in message news:4t2ccc969i3l4h4o3...@4ax.com...
>

>>It's a matter of market. LTSpice allows LT to go after the high
>>margin business, where they want to play.
>

>This claim makes no sense. LTSpice is *only* a *simulation* program. A
>simulation program can't "allow" them to sell parts.

Nonsense. They sell parts because they've made it easy for customers
to design their parts in.

>LTSpice is, essentially, an advertising tool. It simply puts the name LT on
>the desktop. Sure, this has value, but purchasing departments don't buy
>parts based on simulating LT chips on a computer, its, does the part meet
>the performance required, at a cost I am willing to be, with an acceptable
>lead time .

It's a lot more than advertising. I understand that you're jealous of
Mike's rock star status but do try to keep it reasonable. ;-)

[k...@notreal.com]

On Mon, 13 Mar 2017 07:36:20 -0700, John Larkin

Though they try... (they're trying to tell us that we can't use a
particular capacitor).

>
>In most cases, an engineer can even declare an LM317 to be
>sole-source. Much less an LTC2242.
>
>My purchasing dept is not allowed to overrule an engineering decision
>and buy whatever they want. Heaven help companies where they are.

My PPoE allowed purchasing to buy resistors from "anyone" but
capacitor substitutions, had the be cleared by engineering. WHere I
am now, no substutions aren't allowed without really expensive
testing.

>
>I know lots of engineers who pull a part off the LT Spice parts menu,
>sim their circuit, and design in the LTC part.
>
>LTC just sold to ADI for $12 billion, about 10x annual sales. That's
>pretty good.

Thought it was a mere $8B.

[John Larkin]

Sometimes they take us out for sushi.

But I don't want a power design course, especially not eight weeks.
Even I can get tired of sushi.

>
>>>
>>>It's a matter of market. LTSpice allows LT to go after the high
>>>margin business, where they want to play. TI, for instance, has a
>>>completely different marketing model.
>>>
>>
>>Sure. We average about 20% overall parts cost compared to selling
>>price. Half of that is PC boards and packaging. So I don't worry much
>>about parts cost. I do use cheap TI synchronous switchers and external
>>Ls and Cs when it's reasonable, and when I have a lot of them on a
>>board.
>
>Yes, that's *many* times our margin. A buck matters.
>
>>On a production run of, say, 50 or 100 pieces, it's good to minimize
>>the number of line items on the BOM. Every part has to be loaded into
>>feeders and such.
>
>Sure. The nuber of feeders is never a concern for our production (it
>is for our CM but I never make it under their limit). The number of
>devices matters, of course, because it costs more to place a part than
>most parts cost.
>
>>Hey, I use LT Spice for non-LT sims. UniversalOpamp2 is handy.
>
>;-)
>
>My favorite part is "ideal opamp".

I use "e" for that.

[George Herold]

I'm small time, the price difference for LT parts hardly matters.

(Given the cost of box, switches, knobs, connectors, time etc.)
It's nice that someone caters to the smaller customer, I hope some
of that stays with the AD buy.

George H.

[George Herold]

Yeah when is LT going to release "e" and how much is it? :^)
GH

[John Larkin]

I don't recall saying that.

>
>
>>So, no, I don't believe that LTSpice makes much of a difference in sales.
>
>>There wouldn't be a tad of jealousy there, huh?
>
>No. I have given a lot of thought to what is the value of freebee stuff like
>this, and it is not a lot, imo. The reality is, and taking into account your
>valid comment in principle of minimising development time, its simple not a
>rational way to develop products to not do even the most minimal check of
>alternative parts. Its even usually a requirement to design, whenever
>possible, a product where you can second source parts.

Resistors and caps and some ICs are multi-sourced, but not much of the
good stuff is any more.

>
>So, no I don't believe that a competent engineer, using LTSice, will refuse
>to even go on the web for *5 minutes* to check if something else is
>available. Its utter nonsense to suggest that this wouldn't happen. So,
>LTSpice cannot possibly be a genuine *cause* to buy an LT part. The LT part
>will be compared to another part, and the then optimum chosen, and it wont
>matter whether LTSpice is there or not.

But if I get a good sim of an LTC part and it's not expensive, I just
use it. Their stuff works and doesn't get randomly EOLd like Maxim.

Here's a 2-channel 1200 volt pulse generator.

https://dl.dropboxusercontent.com/u/53724080/PCBs/T840_E1.jpg

(Nice layout, no? I did that one myself.)

I needed a 1400 volt supply, so I pulled up the LTC3803 sim, ran it,
and it looked great so I specified the part and moved on to the hard
parts. It worked just as predicted. (U17, tiny 6-pin bugger, cost
$1.32.)

Was I a Bad Engineer?

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

[John Larkin]

I expect that he has some stock options.

[John Larkin]

I like it because it doesn't need a power supply. Must be solar
powered or something.

What the difference between e and e2? Just polarity? The HELP doesn't
say.

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

[Terry Newton]

On Mon, 13 Mar 2017 20:44:27 +0000, Kevin Aylward wrote:

> An engineering product is designed based on technical, objective
> considerations. Not even spending 5 bloody minutes looking for an
> alternative via Google is fantasy. I don't believe for a second that any
> engineer does this. Once alternatives are discovered, an engineer will
> evaluate them to see if they are a better option.

There's more to it than simply finding the cheapest alternative.
A big part of electronic design is minimizing risk, and to do
that I often use LTspice to simulate parts of the circuit.
Sure I look at the alternatives before choosing a part, but
being able to or not able to simulate a circuit is a big factor.
Another factor that sometimes matters a lot is time.

Once LTspice and another free LT tool called FilterCad was very
helpful for our company - we make modules for ANR headsets,
everything was going great until suddenly we started getting a
lot of returns - bad speakers that would pass factory tests but
rattled when our customer assembled them. They were not amused.
Needed to make a speaker tester and fast! To test a speaker
for distortion I needed to output test tones at various
frequencies then filter the output from a sense mic with a
brick-wall high-pass filter set to twice the test frequency.
With FilterCad I typed in my requirements and it spit out a
complicated circuit using a LTC1068. No way I could have
derived all those values on my own with math in the allotted
time let alone test it - I needed a working solution NOW.
LTspice also had this part, so simulated it and found that
I needed to actively drive the bias pin or it leaked lows,
but otherwise the circuit did what I needed to do, just
needed to supply it with a clock that was 100x more than the
pass frequency.. used an ancient 74HC4059 programmable divider
and a FF to turn my fixed clock into a variable clock.

Unfortunately for LT I just needed one chip and a spare
for the factory tester, but it saved us $thousands and
possibly our jobs. If I ever need something like that again
there it is. For the most part I use LTspice to simulate
generic stuff that doesn't need LT parts (unless I want to,
I use bunches of LTC1050 low-offset opamps), but if faced
with something intense like that filter I'll take a design
with a LT part that I can simulate over something untested
any day, even if it costs a bit more. I'm sure LT sells lots
of parts through their free tools - sure it's advertising
but it's also damn useful.

Terry

[Robert Loos]

Am 13.03.2017 um 18:00 schrieb Jim Thompson:
> On Mon, 13 Mar 2017 08:29:22 +0100, Robert Loos <12...@baer-gmbh.com>
> wrote:
>
>> May be it looks a little bit home made and uses odd shortcuts but it has
>> one feature that makes entering schematics as fast as no second program
>> I know:
> [snip]
>>
>> Robert
>
> Monumental BS.
>
> I invite anyone who thinks that the LTspice GUI is "as fast as no
> second program I know" to drop by, if you're in the East Valley area
> of the Phoenix 'burbs, and see a demonstration of a real schematic
> capture.

I'm afraid I won't be in that area in the near future.
I don't know MicroSim. But I know some other more or less expensive
professional software... This video about OrCad for example
https://www.youtube.com/watch?v=dZUPBLNuaHk
is surely not optimized for speed but it shows major lacks in OrCad.
You must draw every wire one by one, exactly hit the pins and sometimes
OrCad ends the wire in free air (2:32). That's what I call BS.
In LTSpice I would just place the components and draw a closed wire loop
through all of them and they are connected. Definitely faster.
And inserting the Switch (3:03), he has to delete the wire, place the
switch and draw another wire. I would just drop the switch over the wire
and it is connected.

>
> Bring your laptop.
>
> At that time we'll locate a mutually acceptable schematic image off
> the web, you can enter it in LTspice, I'll enter with MicroSim PSpice
> Schematics... you'll get your ass whipped >:-}

not sure about that :-). Can you explain how MicroSim makes it faster?

Robert

P.S. just for fun, I tried an astable multivibrator. Can you beat 1:32?

Version 4
SHEET 1 880 680
WIRE -112 -96 -272 -96
WIRE 32 -96 -112 -96
WIRE 208 -96 32 -96
WIRE 320 -96 208 -96
WIRE -112 -48 -112 -96
WIRE 32 -48 32 -96
WIRE 208 -48 208 -96
WIRE 320 -48 320 -96
WIRE -272 48 -272 -96
WIRE -112 80 -112 32
WIRE -64 80 -112 80
WIRE 32 80 32 32
WIRE 32 80 0 80
WIRE 80 80 32 80
WIRE 208 80 208 32
WIRE 208 80 160 80
WIRE 224 80 208 80
WIRE 320 80 320 32
WIRE 320 80 288 80
WIRE -112 112 -112 80
WIRE 320 112 320 80
WIRE 80 160 160 80
WIRE 80 160 -48 160
WIRE 160 160 80 80
WIRE 256 160 160 160
WIRE -272 272 -272 128
WIRE -112 272 -112 208
WIRE -112 272 -272 272
WIRE 320 272 320 208
WIRE 320 272 -112 272
WIRE -112 288 -112 272
FLAG -112 288 0
SYMBOL npn 256 112 R0
SYMATTR InstName Q1
SYMATTR Value BC847A
SYMBOL npn -48 112 M0
SYMATTR InstName Q2
SYMATTR Value BC847A
SYMBOL res -128 -64 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL res 16 -64 R0
SYMATTR InstName R2
SYMATTR Value 47k
SYMBOL res 304 -64 R0
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL res 192 -64 R0
SYMATTR InstName R4
SYMATTR Value 47k
SYMBOL cap 0 64 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 100n
SYMBOL cap 288 64 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL voltage -272 32 R0
SYMATTR InstName V1
SYMATTR Value 5
TEXT -306 312 Left 2 !.tran 100m startup uic
TEXT 432 -48 Left 2 ;1:32 draw the schematic (including values)
TEXT 432 -16 Left 2 ;1:47 Simulation on screen

[Robert Loos]

Am 13.03.2017 um 10:46 schrieb rickman:
> On 3/13/2017 3:29 AM, Robert Loos wrote:
...
>
> I've been through the documentation many times and not all of these
> keystrokes were made apparent to me. Yes, somewhere there is a list of
> all the hotkeys, but mostly they are control keys and weeding through
> the list for the few useful ones is not so easy.

Yes, somewhere in the control panel (the hammer symbol).

> I changed one of the hot keys in the settings so cntl-z was undo as is
> the case in so many windows programs. It was promptly forgotten...

here it works. Maybe it has been fixed.

> I seem to recall fixing some of the waveform colors so they stood out on
> a laptop LCD screen... all gone.

I remember I have changed some (at least the dark blue, which is hard to
see on black) and they're still there.

> If you use the program every day, it can become very familiar. If not,
> the arcane little idiosyncrasies get on your nerves. Why doesn't
> cntl-A select all the text in a text field??? There's a million things
> like this that the few nice features don't make up for.

I fully agree but I have got used to the ones I need and live with it.
Especially with text fields, every program behaves different. If you
want a new line, in some you press return, others want ctrl or alt
return :-(

Robert

[Robert Loos]

Am 13.03.2017 um 13:22 schrieb Kevin Aylward:
> "Robert Loos" wrote in message news:vbuhpd-...@baer-gmbh.com...
>
>> There is no need to place wires from pin to pin! Just place a few
>> parts, then draw a wire right through them and when you end the wire
>> (right click or escape)
>
> I just tried that, and it went and connected up incorrectly.
> Ahmmm...probably because I am unable to use LTpPice.

How did you do it? I never had problems here. Works like a charm.

>> all lines that would short a component magically disappear.
>> Also, if you place a component right over a wire, the piece of wire
>> under the component is automatically deleted.
>
> It didn't used to do that. Mike copied that from me :-)

:-)

> But in reality, I hardly ever use that feature

Sometimes, when I have to insert something, I simply drag the block a
bit away and throw the components in.

>> Frequently used components like resistors, inductors, diodes or ground
>> symbols can be inserted without moving the mouse to a menu by typing
>> r, l, d or g.
>
> So, you don't see the value in having docked, tabbed sidebars that you
> can drag any of the component form any library?

When I hack something into LTSpice, I normally first draw the schematic
and then set the values for the components. When I need an OpAmp, i hit
the component button, type op07 and I have it. Don't care from which
library it comes. Some people may prefer it different.

> http://www.anasoft.co.uk/screenshots.htm
>
> To add model libraries, you just drag drop the file from explorer.
> Symbols for standard models are attached automatically.

cool.

>> Rotate is ctrl-r but mirror is _not_ ctrl-m :-(
>
> There is no rational reason to have the ctrl key as well, SS don't do
> that, its just "r" "m" "f" to rotate, mirror flip up/down. Zoom in/out
> is "i" "o"

"r" is already resistor :-)

> Double-clicking on component does what you expect in windows, as does
> right click popping up a menu :-)

I suppose the original program did not come from the Windows world. It
is like if you use some 'original Linux' programs that have been ported
to Windows. Some things drive you crazy when you are not used to it.

Robert

[k...@notreal.com]

Strawman. It's *never* a 30 minute task to evaluate alternative
parts.

[John Larkin]

Well, it might be for passives and simple discretes. But for a
switcher or something, I generally get an eval board and do some
testing... cap load stability, noise, chip temperature rise, all that.
Might take a day.

I usually test opamps, linear regs, things like that.

[Jim Thompson]

On Tue, 14 Mar 2017 12:03:49 +0100, Robert Loos <12...@baer-gmbh.com>

MicroSim created the original PSpice. You're looking at what OrCAD
could do to f..k it up.

When OrCAD came along and bought out MicroSim I refused to play along
and switch to OrCAD Crapture.

Fortunately, so did many others. So even up into many years after the
Cadence acquisition, MicroSim PSpice Schematics was "supported".

But "support" was a joke. Cadence was systematically removing
features. Fortunately PSpice has always been .INI file based. So an
engineer at ON Semi and I colluded and dug back thru our archives and
restored the original .INI

Support was a joke, nothing was being improved at each maintenance
update, so I quit paying maintenance at v15.7.0.p001

Fortunately I had, long ago, been provided a blanket license, since I
had been one of the main antagonists over the years, finding all the
bugs and quirks, and causing features to be added that suited my IC
design needs.

After an initial purchase of $8,000 in 1987 and maintenance over the
years, I've got about $40K invested.

It's been a good investment... I've designed at least 60 chips with
it, everyone of which came straight out working to spec.

(Though I've got to admit I probably have around 80 chip designs with
almost as good a success rate that were done before CAD ;-)

I won't bother duplicating your example... I want a live competitor...
I love to watch "mouthers" sweat >:-}

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

Thinking outside the box... producing elegant solutions.

[Kevin Aylward]

wrote in message news:lnfecc1jnk23tj5te...@4ax.com...

>>
>>"Expensive" depends on the context. They are small, convenient, and as
>>I noted, very quiet. Two inches away from a 250 MHz, 12 bit ADC, I
>>don't want a lot of switching spikes in my ground plane.
>
>>You've just stated my point about LTSpice, and LT in general. Great
>>stuff, if you're making tens or hundreds a month. Not so great if
>>you're making thousands or hundreds of thousands. TI doesn't give
>>much support for people making tens or hundreds but...
>
>>It's a matter of market. LTSpice allows LT to go after the high
>>margin business, where they want to play.
>
>>This claim makes no sense. LTSpice is *only* a *simulation* program. A
>>simulation program can't "allow" them to sell parts.

>Nonsense. They sell parts because they've made it easy for customers
>to design their parts in.

Nonsense. It is hardly any more work for a competent engineer to go and get
a model from a competitor, and *also* simulate it LTSpice.

Sure, it has *some* value, to include LT models directly, but not a lot, imo

To wit, LTSpice does not guarantee that it will be uses just for LT parts.
I wajor, that of the 3,000,00 downloads, only a low % actually use it to buy
LT parts, and buy other vendors parts instead. Most of those, probably
decide to go into banking once they finish their B.S. E.E. anyway. That's
the bit many seem to be missing here.


So, ones needs to know, how many lazy, incompetent, drunk... engineers there
are that won't do their job and use LTSpice to check out for an optimum
part, and not be bribed by freebees.

>you're jealous of
>Mike's rock star status but do try to keep it reasonable. ;-)

In this world of 7 billion people, Mike is a big a nobody as anyone of us.

Interestingly I just tried in Google:

"spice" "kevin aylward" 4,180 hits

"spice" "mike engelhart" 1080 hits

:-)

And no, the only rock star in this NG, is the one in the purple shirt
playing the blue guitar with cream fingerboard...

http://www.rosierox.com/photos_the_earl_of_derby_cambridge.htm

[Kevin Aylward]

>"John Devereux" wrote in message news:87tw6wq...@devereux.me.uk...

>Yes that is something of a side issue although for most of the "unique"
>parts can be implemented with something else but may be more complicated
>to design. But for specialist applications where volumes are lower I can
>see the attraction of being able to drop in circuit block and have it
>"just work", and furthermore be able to immediately demonstrate and
>verify that with LTSpice.

But could you really sleep at night, knowing that you didn't even *try* to
find another part? What if the engineer in the next cubicle decided to do
so, and then showed to your boss that there was a better and cheaper part?

A key point is that LTSpice runs *any* PSpice/Spice3 model from any vendor,
so its a pop to the competitions website to download their model and run it
in LTSpice

The point being, LTSpice does not force, or ensure people use it to buy
*only* LT parts. Its just a bit more, in your face advertising, and that his
limited value to people like engineers, who almost invariable evaluate based
on objective values.

My estimate is that LTSpice is used to buy more of other vendors products,
then their own. LT parts are expensive.

[Kevin Aylward]

"John Larkin" wrote in message

news:r4neccteoeo6npau0...@4ax.com...

Probably, but company bosses are not necessarily known to be good the people
that actually make them their money.

https://en.wikipedia.org/wiki/Bob_Widlar

"Talbert handling the fabrication and Widlar handling the design, they ruled
the world and led the world in linear integrated circuits for a couple of
decades."[

"Widlar and Talbert realized that the founders of Fairchild did not intend
to share their windfall profits with the designers."

[Kevin Aylward]

>wrote in message news:1e7gccp4r9ghq2gqo...@4ax.com...

>
>>Engineering is expensive. Risk can be expensive. Performance can be
>>valuable. Getting a product to market matters. There's more to
>>engineering than minimizing the BOM cost.
>
>Sure, but one needs to step back a bit here, and examine reality.
>
>Are you really claiming that a competent engineer is not even going to
>spend 30 mins on the web. Like *30 min* out of months of development costs,
>simply to check out if another suitable part might even exist?

>Strawman.

Not at all

>It's *never* a 30 minute task to evaluate alternative
>parts.

That is not the point. What part of "check out" and "exists" did you miss?

The only reason any competent engineer, that is designing for major
production runs, is not going to the most basic of "does anther part even
exist", is if he has no idea that an alternative might exist. i.e. he was a
clueless engineer. Dah..Gee,. looks like I have to go with this..dah...

What I can say, is that if I were hiring engineers, hiring an engineer that
is bribed by a freebe bit of kit from a vendor, such that he wont even
attempt to find a more optimum part, would not be at the top of my resume
list.

[Kevin Aylward]

>"Terry Newton" wrote in message news:oa87j7$11bh$1...@gioia.aioe.org...

On Mon, 13 Mar 2017 20:44:27 +0000, Kevin Aylward wrote:

> >An engineering product is designed based on technical, objective
>> considerations. Not even spending 5 bloody minutes looking for an
>> alternative via Google is fantasy. I don't believe for a second that any
>> engineer does this. Once alternatives are discovered, an engineer will
>> evaluate them to see if they are a better option.

>There's more to it than simply finding the cheapest alternative.

That's why I wrote "better option"

>A big part of electronic design is minimizing risk, and to do
>that I often use LTspice to simulate parts of the circuit.
>Sure I look at the alternatives before choosing a part, but
>being able to or not able to simulate a circuit is a big factor.
>Another factor that sometimes matters a lot is time.

Sure, no one has denied that, but are you, personably, so incompetent that
you are not able to load in the competitions models form their websites in
reasonable time?

I doubt it.

So, sure, its useful to have the model includes, but its is trivial detail,
only of value to those engineers that probably would be better employed
basket weaving.

I am not talking about the minor, one off, shit, lets just see if this works
bit. I am referring to standard, professional long term product design,
where one *IS* subjected to a whole host of constraints like, second
sourcing, availability, cost, performance etc...

I just don't accept you achieve that by simply using parts, bribed to you,
by their inclusion in a freebee spice program.

>Unfortunately for LT I just needed one chip

And illustrates part of the argument I am making.

[John Larkin]

I don't drink much. A small beer, or maybe a rum+coke, two or three
times a week.

>>you're jealous of
>>Mike's rock star status but do try to keep it reasonable. ;-)
>
>In this world of 7 billion people, Mike is a big a nobody as anyone of us.
>
>Interestingly I just tried in Google:
>
>"spice" "kevin aylward" 4,180 hits
>
>"spice" "mike engelhart" 1080 hits

Super Spice 53,000,000 hits, but not about circuit simulators.

LT Spice 747,000 hits, but on topic.

[Jim Thompson]

On Tue, 14 Mar 2017 20:28:57 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

>wrote in message news:lnfecc1jnk23tj5te...@4ax.com...

[snip]

>
>>Nonsense. They sell parts because they've made it easy for customers
>>to design their parts in.
>
>Nonsense. It is hardly any more work for a competent engineer to go and get
>a model from a competitor, and *also* simulate it LTSpice.
>

[snip]

Therein lies the rub... every frickin' manufacturer is heading toward
encrypted models that only run on their own version of simulator, or,
like Microchip, have PhD monkeys rolling out models using tables or IF
statements that hardly ever converge.

[Tim Wescott]

On Tue, 14 Mar 2017 14:05:35 -0700, Jim Thompson wrote:

> On Tue, 14 Mar 2017 20:28:57 -0000, "Kevin Aylward"
> <kevinR...@kevinaylward.co.uk> wrote:
>
>>wrote in message news:lnfecc1jnk23tj5te...@4ax.com...
>
> [snip]
>>
>>>Nonsense. They sell parts because they've made it easy for customers
>>>to design their parts in.
>>
>>Nonsense. It is hardly any more work for a competent engineer to go and
>>get a model from a competitor, and *also* simulate it LTSpice.
>>
> [snip]
>
> Therein lies the rub... every frickin' manufacturer is heading toward
> encrypted models that only run on their own version of simulator, or,
> like Microchip, have PhD monkeys rolling out models using tables or IF
> statements that hardly ever converge.
>
> ...Jim Thompson

They probably have the notion that they'll lock you into using only their
parts.

For me, it's more that they drive me away from using their parts, but
hey, I'm a known weirdo.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!

[Terry Newton]

On Tue, 14 Mar 2017 20:42:36 +0000, Kevin Aylward wrote:

>>"Terry Newton" wrote in message news:oa87j7$11bh$1...@gioia.aioe.org...
>

>>There's more to it than simply finding the cheapest alternative.
>
> That's why I wrote "better option"
>
>>A big part of electronic design is minimizing risk, and to do that I
>>often use LTspice to simulate parts of the circuit.
>>Sure I look at the alternatives before choosing a part, but being able
>>to or not able to simulate a circuit is a big factor. Another factor
>>that sometimes matters a lot is time.
>
> Sure, no one has denied that, but are you, personably, so incompetent
> that you are not able to load in the competitions models form their
> websites in reasonable time?

uhh... what other switched capacitor active filter chip even
has a spice model? LTspice is also a behavioral simulator (why
it's so fast for switchers) and LT took the time to write behavior
simulations for almost all their analog chips. Other companies,
except for standard parts like opamps, not so much. Not that
I need specific models for simple stuff like that.

> So, sure, its useful to have the model includes, but its is trivial
> detail, only of value to those engineers that probably would be better
> employed basket weaving.

It is not trivial when under the gun. And I suck at making baskets.

> I am not talking about the minor, one off, shit, lets just see if this
> works bit. I am referring to standard, professional long term product
> design, where one *IS* subjected to a whole host of constraints like,
> second sourcing, availability, cost, performance etc...

My case was a one-off, true, but it was an extremely important
one-off and the solution ended up working so well that if I did
need something like that again I would not hesitate to reuse it.

> I just don't accept you achieve that by simply using parts, bribed to
> you, by their inclusion in a freebee spice program.

Don't have to accept that because I don't, 99% of the stuff
I use LTspice for does not involve using LT parts. I used that
as an example of how it can matter - just because it was a one-off
for me *that time* doesn't mean a similar problem is always a
one-off, could have just as easily been for mass production.

>>Unfortunately for LT I just needed one chip
>
> And illustrates part of the argument I am making.

The claim was that LT sells lots of chips by giving away free
tools, you refuted that claim, I told a story about how once
LTspice saved my bacon. I needed a filter with 0db at center
more than 60db cut at half that frequency, LT gave me the
tools to do that with very little effort (more time to design
the rest of the stuff and write the code) and the end result
worked perfectly. I did look at alternatives, LT's solution
was the best by far. Sure it's not a cheap chip, but for what
it did, the price wasn't bad.. ~$12 single for a precision
70db/octave filter with practically no ripple. How many I
needed personally is not relevant, DK stocks thousands of
them so someone is using the part. I have no doubt that
LT sells oodles of parts because the tools they give away
make the process of using the parts easy and relatively
risk-free.

That said, I still wish it had a better GUI :-)
When I get a chance I'm evaluating SS, it does seem to
have better measurement options.. it's not either/or...

Terry

[JM]

There was nothing wrong with the OrCAD DOS products - it's hard to think
how the SDT and PCB products could be improved upon. When they moved to
Windows - different story.

[JM]

Kevin, you might be surprised at the number of analogue engineers who
design by stitching together application notes. I would say it's the
great majority. I never really appreciated the fact until I went
freelance and was exposed to dozens of design teams, but the reality is
that only a low percentage of the engineers doing board and system level
design are competent in their craft.

What I usually see is that if an engineer manages to cobble together
something in LtSpice (usually from the supplied examples) that meets the
technical specs of whatever it is they've been tasked to do, then the
design stage is over.

[John Larkin]

On Tue, 14 Mar 2017 23:03:11 +0000, JM <dontreply...@gmail.com>
wrote:

I have boards with 1100 parts. 10-layer boards with several FPGAs and
22 power supplies. Boards full of Eclips Plus logic and SiGe
comparators and power PHEMTS and RF transistors. Boards that sell for
$11,000. If I can knock out a switcher design in an hour, using an LTC
part, I can move on to the hard/fun stuff.

If I expect to build thousands of something relatively cheap (which I
prefer to not do!) I might spend some time evaluating cheaper parts,
which might not have a decent Spice model at all.

On that 22-supply board, I used mostly TPS54302 synchronous switchers,
very cool little parts. I breadboarded five different voltage outputs
with different inductors and caps and loop compensations. I have never
got WebBench to load on my PC.

[John Miles, KE5FX]

On Monday, March 13, 2017 at 10:26:48 AM UTC-7, Kevin Aylward wrote:
>
> So, no, I don't believe that LTSpice makes much of a difference in sales.

It's not a sales tool, IMO, but a support tool. Imagine that your job is to
answer the phone when people call with questions about one of your company's
hundreds of SMPS controllers. Being able to say "Send us a simulation"
or "Check out this example" has got to be more or less priceless.

That'll be why they originally called it "SwitcherCAD." It wasn't originally
meant to model opamps and 6L6s and stuff.

-- john, KE5FX

[k...@notreal.com]

It takes longer than 30 minutes to search for a simple part[*] and a
*lot* longer to just understand the datasheet.

[*] I play the FAEs off each other for this step but I still have to
talk to them.

>
>I usually test opamps, linear regs, things like that.

You don't test SMPSs?

[k...@notreal.com]

On Tue, 14 Mar 2017 20:31:14 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:

>>wrote in message news:1e7gccp4r9ghq2gqo...@4ax.com...
>
>
>>
>>>Engineering is expensive. Risk can be expensive. Performance can be
>>>valuable. Getting a product to market matters. There's more to
>>>engineering than minimizing the BOM cost.
>>
>>Sure, but one needs to step back a bit here, and examine reality.
>>
>>Are you really claiming that a competent engineer is not even going to
>>spend 30 mins on the web. Like *30 min* out of months of development costs,
>>simply to check out if another suitable part might even exist?
>
>>Strawman.
>
>Not at all

You're being ridiculous.

>
>>It's *never* a 30 minute task to evaluate alternative
>>parts.
>
>That is not the point. What part of "check out" and "exists" did you miss?
>
>The only reason any competent engineer, that is designing for major
>production runs, is not going to the most basic of "does anther part even
>exist", is if he has no idea that an alternative might exist. i.e. he was a
>clueless engineer. Dah..Gee,. looks like I have to go with this..dah...

Wait a minute. You said competent engineers optimized the designs
even for low volume production.

You can't even search TI for an SMPS in a half an hour. It takes
their FAE longer than that to find the best fit for some applications
(ones he hasn't already searched).

>
>What I can say, is that if I were hiring engineers, hiring an engineer that
>is bribed by a freebe bit of kit from a vendor, such that he wont even
>attempt to find a more optimum part, would not be at the top of my resume
>list.

For a prduction run of a hundred units? Please!

[Neon John]

On Mon, 13 Mar 2017 09:32:32 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:


>If a simulator does not directly support worst case analyses, its dead in
>the water as far as IC design in concerned. Period.

What your narcissistic personality disorder will not let you
acknowledge is that, perhaps with one or two exceptions, nobody here
gives a flying fatal f**k what you do or what it takes to design ICs.

We real engineers, you know, the ones who design products that sell
and make the company profitable, especially people like myself and the
other John who owns the company, buy parts based on data sheet specs,
design circuits, sim parts of the circuit that are questionable and
then spin board that work first time in most cases. We couldn't care
less what goes on inside the epoxy.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address

[k...@notreal.com]

Exactly. For low volume, high margin, production it doesn't make
sense to spend a lot of time on support circuits. High-volume, low
margin (they go together) designs, one spends a *lot* longer than a
half an hour optimizing things.

[rickman]

On 3/14/2017 8:38 PM, Neon John wrote:
> On Mon, 13 Mar 2017 09:32:32 -0000, "Kevin Aylward"
> <kevinR...@kevinaylward.co.uk> wrote:
>
>
>> If a simulator does not directly support worst case analyses, its dead in
>> the water as far as IC design in concerned. Period.
>
> What your narcissistic personality disorder will not let you
> acknowledge is that, perhaps with one or two exceptions, nobody here
> gives a flying fatal f**k what you do or what it takes to design ICs.
>
> We real engineers, you know, the ones who design products that sell
> and make the company profitable, especially people like myself and the
> other John who owns the company, buy parts based on data sheet specs,
> design circuits, sim parts of the circuit that are questionable and
> then spin board that work first time in most cases. We couldn't care
> less what goes on inside the epoxy.

If you care so little, why are you posting?

--

Rick C

[John Larkin]

Spend a couple of days to save $50!

[k...@notreal.com]

Seems that's Kevin's business plan. He could get rich that way.

[k...@notreal.com]

On Tue, 14 Mar 2017 17:26:44 -0700 (PDT), "John Miles, KE5FX"
<jmi...@gmail.com> wrote:

>On Monday, March 13, 2017 at 10:26:48 AM UTC-7, Kevin Aylward wrote:
>>
>> So, no, I don't believe that LTSpice makes much of a difference in sales.
>
>It's not a sales tool, IMO, but a support tool. Imagine that your job is to
>answer the phone when people call with questions about one of your company's
>hundreds of SMPS controllers. Being able to say "Send us a simulation"
>or "Check out this example" has got to be more or less priceless.

Or more importantly, avoid the calls entirely because the user can see
what's (not) happening.

[M Philbrook]

In article <7YKdnZN-tr7j5ljF...@giganews.com>,
kevinR...@kevinaylward.co.uk says...
>
> "M Philbrook" wrote in message
> news:MPG.332f37eee...@news.eternal-september.org...
>
> In article <o9veuf$50c$1...@dont-email.me>, gnu...@gmail.com says...
> >
> > Every time I want to do something with LTspice I have to fight the UI
> > something wicked. Doing anything relating to commands is pure torture.
> >
> >> I eventually figured out how to do what I wanted, but it is amazing how
> >> poor not only the UI is, but the documentation. I have learned
> >> programming languages by reading the manuals. But I can't decipher the
> >> .MEAS statement in LTspice along with many other features.
>
> > Please be advised, LTspice and those like it are real programs designed
> >for serious users in mind looking for real productivity tools for those
> >that are PRODUCTIVE.
>
> Pardon?

Did you fart ?
> http://www.anasoft.co.uk/worstcase.htm
>
> LTSpice is a freebee that lacks major key features for productive,
> professional use, imo...
>
> Anyone can piss about and make a one off work.
>

[rickman]

On 3/14/2017 4:28 PM, Kevin Aylward wrote:
> wrote in message news:lnfecc1jnk23tj5te...@4ax.com...
>
>>>
>>> "Expensive" depends on the context. They are small, convenient, and as
>>> I noted, very quiet. Two inches away from a 250 MHz, 12 bit ADC, I
>>> don't want a lot of switching spikes in my ground plane.
>>
>>> You've just stated my point about LTSpice, and LT in general. Great
>>> stuff, if you're making tens or hundreds a month. Not so great if
>>> you're making thousands or hundreds of thousands. TI doesn't give
>>> much support for people making tens or hundreds but...
>>
>>> It's a matter of market. LTSpice allows LT to go after the high
>>> margin business, where they want to play.
>>
>>> This claim makes no sense. LTSpice is *only* a *simulation* program. A
>>> simulation program can't "allow" them to sell parts.
>
>> Nonsense. They sell parts because they've made it easy for customers
>> to design their parts in.
>
> Nonsense. It is hardly any more work for a competent engineer to go and
> get a model from a competitor, and *also* simulate it LTSpice.

It wouldn't be if they didn't worry about the competition and bring out
their own spice with slightly incompatible models.

> Sure, it has *some* value, to include LT models directly, but not a lot,
> imo
>
> To wit, LTSpice does not guarantee that it will be uses just for LT
> parts. I wajor, that of the 3,000,00 downloads, only a low % actually
> use it to buy LT parts, and buy other vendors parts instead. Most of
> those, probably decide to go into banking once they finish their B.S.
> E.E. anyway. That's the bit many seem to be missing here.
>
>
> So, ones needs to know, how many lazy, incompetent, drunk... engineers
> there are that won't do their job and use LTSpice to check out for an
> optimum part, and not be bribed by freebees.

I'm raising my hand...

--

Rick C

[Jim Thompson]

On Tue, 14 Mar 2017 22:43:59 +0000, JM <dontreply...@gmail.com>
wrote:

Yep, I actually liked SDT, then there came Crapture >:-}

[Jim Thompson]

On Tue, 14 Mar 2017 23:03:11 +0000, JM <dontreply...@gmail.com>
wrote:

Boy, ain't that the truth! I don't know how many projects I've lost,
saying, "You're not listening, so I'm outta here."

>
>What I usually see is that if an engineer manages to cobble together
>something in LtSpice (usually from the supplied examples) that meets the
>technical specs of whatever it is they've been tasked to do, then the
>design stage is over.
>

My personal burn is they come to me with a board heavily populated by
OpAmps everywhere, and want me to simply put it all on a chip. When I
ask for an overall system spec, they get all grousey. It's hard for
me to convince these dorks that an OpAmp function, on-chip, can often
be replaced with a couple of transistors... if any are needed at all.

Some of those very dorks lurk here >:-}

[Jim Thompson]

We call people who think like you "Blue Wire Queens" >:-}

Chips generally aren't tweakable... they either work, or they don't.

[John Larkin]

On Tue, 14 Mar 2017 17:26:44 -0700 (PDT), "John Miles, KE5FX"
<jmi...@gmail.com> wrote:

Most of the parts pages on the LT site have example LT Spice sims that
you can download and run instantly, and then modify for your
application.

Of course, you have to beautify them, too. They are usually very ugly.

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

[Phil Hobbs]

On 03/14/2017 05:10 PM, Tim Wescott wrote:
> On Tue, 14 Mar 2017 14:05:35 -0700, Jim Thompson wrote:
>
>> On Tue, 14 Mar 2017 20:28:57 -0000, "Kevin Aylward"
>> <kevinR...@kevinaylward.co.uk> wrote:
>>
>>> wrote in message news:lnfecc1jnk23tj5te...@4ax.com...
>>
>> [snip]
>>>
>>>> Nonsense. They sell parts because they've made it easy for customers
>>>> to design their parts in.
>>>
>>> Nonsense. It is hardly any more work for a competent engineer to go and
>>> get a model from a competitor, and *also* simulate it LTSpice.
>>>
>> [snip]
>>
>> Therein lies the rub... every frickin' manufacturer is heading toward
>> encrypted models that only run on their own version of simulator, or,
>> like Microchip, have PhD monkeys rolling out models using tables or IF
>> statements that hardly ever converge.
>>
>> ...Jim Thompson
>
> They probably have the notion that they'll lock you into using only their
> parts.
>
> For me, it's more that they drive me away from using their parts, but
> hey, I'm a known weirdo.
>

The LT switcher models are very good, in my limited experience. Mike
says that that's because they're real transistor-level models and so
have to be encrypted.

(I try to use LM2594s for everything, myself. No modelling required.) ;)

SPICE IC models are sufficiently crappy that if I'm relying on them for
anything delicate I have to breadboard anyway. Discrete circuitry is
the only place I'm prepared to actually trust it at all.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

[George Herold]

Grin, raises hand. App notes or circuits ripped out of AoE.
(Probably more of the later... do they even make good app notes any more?)

George H.

[Kevin Aylward]

"Neon John" wrote in message
news:im2hcctksu3tsojhc...@4ax.com...

On Mon, 13 Mar 2017 09:32:32 -0000, "Kevin Aylward"
<kevinR...@kevinaylward.co.uk> wrote:


>If a simulator does not directly support worst case analyses, its dead in
>the water as far as IC design in concerned. Period.

>What your narcissistic personality disorder will not let you
>acknowledge is that, perhaps with one or two exceptions, nobody here
>gives a flying fatal f**k what you do or what it takes to design ICs.

Actually, I believe quite a few are interested in IC design. This is an
electronics NG, for people interested in electronics. There was at least one
post, that indicated very positively on having a description of what is
involved in IC design. Its specialised knowledge, that you don't gain unless
being involved in it.

Furthermore, I made it very clear that I was specifically making comments as
applied to IC design. I am well aware requirements for board level design
are different. I was a board designer for 15 years.

>We real engineers, you know, the ones who design products that sell

I hear the trumpet blowing...

[Kevin Aylward]

"John Larkin" wrote in message

news:ielgccl18cg0o46s0...@4ax.com...

>>you're jealous of
>>Mike's rock star status but do try to keep it reasonable. ;-)
>
>In this world of 7 billion people, Mike is a big a nobody as anyone of us.
>
>Interestingly I just tried in Google:
>
>"spice" "kevin aylward" 4,180 hits
>
>"spice" "mike engelhart" 1080 hits

>Super Spice 53,000,000 hits, but not about circuit simulators.

>LT Spice 747,000 hits, but on topic.

The point was about who was the biggest rock star, Mike or Me, not Spice.
The spice bit was just a filter to avoid counting that Newfoundland
minister...

I wasn't aware mike played guitar at all, if he does, he's probably shit :-)