"John Larkin" wrote in message news:p9ebcct498ug963d9npu0054ljaeaa8tpp@4ax.com... On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote:>"John Larkin" wrote in message >news:pi2bcc1mmrc1027fui30jm0p0rr39n4nh8@4ax.com... > >On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward" ><kevinRemovAT@kevinaylward.co.uk> wrote: > >>"M Philbrook" wrote in message >>news:MPG.332f37eeea23385398a015@news.eternal-september.org... >> >>In article <o9veuf$50c$1@dont-email.me>, gnuarm@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. > >>LT Spice has sold a lot of LT parts.Maybe, maybe not. How do know? What physical evidence is there of that? -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
LTspice, a great program, but that UI!
Started by ●March 10, 2017
Reply by ●March 13, 20172017-03-13
Reply by ●March 13, 20172017-03-13
"Kevin Aylward" wrote in message news:mZ-dnWN2AsZz11vFnZ2dnUU7-b_NnZ2d@giganews.com...>"Cursitor Doom" wrote in message news:oa4gd2$h3o$12@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. -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●March 13, 20172017-03-13
On 3/13/2017 3:29 AM, Robert Loos 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: > 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!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
Reply by ●March 13, 20172017-03-13
"Robert Loos" wrote in message news:vbuhpd-a4d.ln1@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 :-) -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●March 13, 20172017-03-13
Reply by ●March 13, 20172017-03-13
>"Cursitor Doom" wrote in message news:oa4h2j$h3o$13@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>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.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. -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●March 13, 20172017-03-13
On Mon, 13 Mar 2017 08:42:25 -0000, "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote:>"John Larkin" wrote in message >news:p9ebcct498ug963d9npu0054ljaeaa8tpp@4ax.com... > >On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward" ><kevinRemovAT@kevinaylward.co.uk> wrote: > >>"John Larkin" wrote in message >>news:pi2bcc1mmrc1027fui30jm0p0rr39n4nh8@4ax.com... >> >>On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward" >><kevinRemovAT@kevinaylward.co.uk> wrote: >> >>>"M Philbrook" wrote in message >>>news:MPG.332f37eeea23385398a015@news.eternal-september.org... >>> >>>In article <o9veuf$50c$1@dont-email.me>, gnuarm@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. >> >> > > >>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. And because the LTC people physically told me so last week. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●March 13, 20172017-03-13
On Mon, 13 Mar 2017 08:33:47 -0000, "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> wrote:>wrote in message news:4t2ccc969i3l4h4o36f52hsaa1saj63du7@4ax.com... > >On Sun, 12 Mar 2017 19:58:33 -0700, John Larkin ><jjlarkin@highlandtechnology.com> wrote: > >>On Sun, 12 Mar 2017 22:46:37 -0400, krw@notreal.com wrote: >> >>>On Sun, 12 Mar 2017 19:20:41 -0700, John Larkin >>><jjlarkin@highlandtechnology.com> wrote: >>> >>>>On Sun, 12 Mar 2017 20:15:18 -0400, krw@notreal.com wrote: >>>> >>>>>On Sun, 12 Mar 2017 19:42:31 -0000, "Kevin Aylward" >>>>><kevinRemovAT@kevinaylward.co.uk> wrote: >>>>> >>>>>>"John Larkin" wrote in message >>>>>>news:pi2bcc1mmrc1027fui30jm0p0rr39n4nh8@4ax.com... >>>>>> >>>>>>On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward" >>>>>><kevinRemovAT@kevinaylward.co.uk> wrote: >>>>>> >>>>>>>"M Philbrook" wrote in message >>>>>>>news:MPG.332f37eeea23385398a015@news.eternal-september.org... >>>>>>> >>>>>>>In article <o9veuf$50c$1@dont-email.me>, gnuarm@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... > >>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. > >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 . > > >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. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●March 13, 20172017-03-13
On Mon, 13 Mar 2017 08:29:22 +0100, Robert Loos <1209@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]> >RobertMonumental 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 -- | 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.
Reply by ●March 13, 20172017-03-13
On Sun, 12 Mar 2017 16:29:11 -0500, John S <Sophi.2@invalid.org> wrote:>On 3/12/2017 4:16 PM, John Larkin wrote: >> On Sun, 12 Mar 2017 19:39:18 -0000, "Kevin Aylward" >> <kevinRemovAT@kevinaylward.co.uk> wrote: >> >>> "Jim Thompson" wrote in message >>> news:ia4bcc9e1dh1uq7pf004t2p4on11gokme7@4ax.com... >>> >>> On Sun, 12 Mar 2017 16:46:53 -0000, "Kevin Aylward" >>> <kevinRemovAT@kevinaylward.co.uk> wrote: >>> >>>> "M Philbrook" wrote in message >>>> news:MPG.332f37eeea23385398a015@news.eternal-september.org... >>>> >>>> In article <o9veuf$50c$1@dont-email.me>, gnuarm@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
