How to improve LTSpice

[dreadpirateroberts]

Simple Question:

How can LTSpice be improved?

• What are its good points?
• What are its bad points?
• What features are missing?
• If you had to rewrite the package from the start, what would you do differently?
• Would you like it to have more "Windows Like" features (CTRL-C, CTRL-V to copy and paste etc)?
• Do you need a more user friendly experience (like moving windows from one monitor to another)
• Are there any simulation features you would like to see integrated?
• What do you think of the schematic editing page? Could this be improved?

If you have experience of other simulation packages, what feature do these packages have that you wished LTSpice had?

 

[atferrari]

Are you part of the team mantaining LTSpice?

 

[dreadpirateroberts]

I may well be! LTspice is the number one electronic simulator, but can it be improved? It has its quirks, but you get to love these quirks after a while. Are there features missing that could be included? How is the user interface? I am interested in your experience of LTspice, both good and bad. From my personal experience, I would like to see the user manual completely rewritten. This could be much more comprehensive and written in a way that mere mortals can understand. It could be filled with more examples and hyperlinks to example circuits instead of having to crawl through the internet looking for a solution. I have gotten used to the user interface, but I have heard people saying they would like to see it have a look and feel similar to that of Windows. I always want more speed from LTspice, but that might be a step too far.

Anyone else got any other thoughts?

 

[crutschow]

It would be nice to have a Monte Carlo option that randomly varies all the components (including transistor gain) over their tolerance range to see the variation in circuit performance from this.
That's very handy for a worst-case analysis of the circuit (which can be rather tedious otherwise).

I used to use Electronic Workbench (now part of Multisim) which had (has) that feature.

 

[alec_t]

I find the program really useful and can forgive its little quirks.
I would welcome customisable keyboard short-cuts, and in Control Panel it would be nice to have more of the settings remembered between program invocations.
As for making it more Windows-like, fine providing existing functions don't get compromised. I believe in function being far more important than form and would hate to see the program dumbed down, or its operation slowed down, just to make the interface pretty.
For those with less than 20-20 vision, a wider choice of icon sizes would be helpful.
A global (as well as individual) setting for scalable symbol font size would be handy.
I agree the Help manual could do with revision/expansion, e.g by providing some numerical examples of circuit element syntax. Help is there, but it's somewhat cryptic.

 

[crutschow]

Thought of another small change.
It would be nice if the plots retained any customized scale settings from one run to the next.
Thus if I've set an expanded scale, I don't have to reset it every time I run the simulation.

 

[dreadpirateroberts]

Hi crutschow/alec_t

Perfect answers. Thanks very much. This is just the sort of feedback I wanted. I agree with the customizable scaling both on the x and the y axes. We could implement this by saving both the x and y settings in the .plt file such that when you save the plot settings and rerun the simulation it autoscales to the desired x and y setting.

Worst case analysis would be good too - a variation on Monte Carlo. There is an apps note written by one of our engineers that shows how to do this, but it would be nice to have this integrated. His apps note uses the math functions in LTspice rather than a dedicated function.

Here is the apps note, just for reference:
Worst Case Analysis LTspice

I agree with the icon sizes too... and I can see me agreeing with it more as the years go by!

I think all of us would prefer to keep the functionality (and speed) of LTspice rather than have a prettier GUI, but this point needs to be re-enforced regardless.

For anyone else with inputs, please keep the comments coming..!

Thanks once again...

 

[kubeek]

I got a few things:
It sometimes crashes when I have a long simulation and I am clicking into the circuit to change what trace I want to see, and ltspice is still trying to load the old trace

updating by downloading a thousand tiny tar.gz packages takes a huge amount of time, maybe downloading and automatically installing a complete new package would be a lot faster

but mainly , please improve the documentation and visibility of the operators, functions, and variables that can be used either for plotting or for setting up behavioral sources. Compare it to the now discontinued micro-cap, that has wonderful selection of operators and they are readily accessible for the plot. Also it has a lot more posibilites to combine them (may have changed since I last needed this) (or it has the same possibilities, but you have to browse decade old tutorials and some of them are not correct anymore)

 

[alec_t]

updating by downloading a thousand tiny tar.gz packages takes a huge amount of time, maybe downloading and automatically installing a complete new package would be a lot faster

I would hope that didn't result in user-added models getting wiped out. The present update arrangement, though sluggish, does at least have the decency to avoid that. It's generous of Analog Devices to provide a free tool that allows third-party models to be added and I hope that continues to be the case so that students and hobbyists are encouraged to hone their electronics skills.

 

[schmitt trigger]

I echo alec_t's sentiments.

LTSpice, to be freeware, is an extremely capable simulation program.

And although it has its quirks and limitations (like absolutely every software program), both LT and AD have resisted the temptation to monetize on its popularity.
My personal beef is with the sparse documentation, but the software being so popular, there are literally dozens of web tutorials. A little googling can get you a long way to solve an issue.

 

[Ylli]

Would be nice if user selected trace colors could be remembered globally. The second trace defaults to blue, and I find blue very hard to see. Would be nice if I could set it to something else once and have it saved instead of having to change the trace color every time I open things.

 

[alec_t]

Would be nice if user selected trace colors could be remembered globally.

They can. Go to Tools/Color preferences/Waveform.

 

[Ylli]

They can.

Thank you! Not sure where I was trying to set it, but it wasn't 'sticking'.

 

[dreadpirateroberts]

Blue does not display very well on my monitor, so I changed it too. You can also change the thickness of the schematic traces, background color of the schematic and schematic wire colors too. Tools - Control Panel - Drafting Options. While you are changing things, go into Tools - Control Panel - Operation and change the RAM for Fast Access Conversion to 90%. This should make it run faster

Thanks as always for the continued inputs. I will feed these back to the team.

Any more thoughts gratefully received

 

[alec_t]

The dreaded "Time step too small" message pops up frequently, but with no on-screen clue as to why. Presumably the Spice engine itself knows perfectly well why, and it would be nice if it would condescend to display some hints as to how to overcome the issue to us mere mortals .

 

[simonbramble]

alec_t - normally switching to Alternate mode flushes out such issues

Tools -> Control Panel -> SPICE tab ->change solver from Normal to Alternate... but I agree - some clue as to what is causing the issue would be quite welcome

 

[alec_t]

I usually find it's circuits with reactive components which can give the time step error. Tweaking an L or a C to by adding some parasitic value to make it a non-ideal component generally gets rid of the error.