Can anybody suggest a free circuit simulator?

Hi everyone,

I need to design a dc-dc converter. I already chosen two chips from Maxim (Max685 and Max8614). My problem is that I can't find a proper circuit simulation tool to verify my design. I used to design analog chips by using Cadence Virtuoso custom design platform in the college. This is my first time to design a pcb circuit rather than a chip, so I extremely wonder there is any easy to learn tool to be used by me as a beginner.

Cheers.

I use LTSpice from linear

http://www.linear.com/designtools/software/switchercad.jsp

Depending on your requirements, you could look at the demo version of Tina: http://www.tina.com/

A forum search will also flag other softwares that are suitable.

Dave

http://focus.ti.com/docs/toolsw/folders/print/tina-ti.html -- TINA-TI from texas instruments is user friendly.

There are also some suggestions here: http://forum.allaboutcircuits.com/showthread.php?t=9538

Dave

http://www.gnu.org/software/gnucap

http://ngspice.sourceforge.net

(* jcl *)

Good suggestions, John. I will copy your post over to the Useful websites for electronics thread in the Electronics Resources forum.

Dave

thanks you guys so much.

Yes, thanks ever so much.

TINA-TI was really the thing for me. With fragmented knowledge and little practise, it's best to start from the beginning.
I do have a copy of ElectriCAD (AutoDesk) and also a few others, but it will take a while i can see.... lol



Very grateful !


S.

I'd like to suggest my "baby", NL5 (http://nl5.sidelinesoft.com). Just released for public. Free with some limitations, however might be enough for many tasks. My colleagues already switched from Tina and LTSpice.

Thanks,
Alexei.

you can use the demo version of NI's multisim circuit simulation

http://www.analog.com/en/design-tools/dt-multisim-spice-program-download/design-center/index.html

Alexei Smirnov said:

I'd like to suggest my "baby", NL5 (http://nl5.sidelinesoft.com). Just released for public. Free with some limitations, however might be enough for many tasks. My colleagues already switched from Tina and LTSpice.

Thanks,
Alexei.

Click to expand...

Does the demo version expire, or is it a rolling feature limited license?

Dave

Hello,

The website does not mention expiring of the demo.

Without a license, NL5 operates as a Demo version. In the Demo version many features are not available, and the number of components in the schematic is limited (currently to 20). However, the Demo version allows simulation of old schematics with an unlimited number of components, although it does not allow any editing or saving of those schematics.
While the Demo version is quite suitable for students and amateurs, professionals might consider obtaining one of the following full-function licenses:
Free 30 day Trial License — Provides full functionality on a single PC for 30 days. The license can be issued for a specific PC only once. Use this license to explore NL5's possibilities. Learn more and order…

Click to expand...

Greetings,
Bertus

NL5 working as "Demo" version if there is no license at all, or if trial/temporary license expired. In Demo, number of components is limited, and not all features are available. However, you can still simulate (without editing) big circuits you've created with the license, so you can see the results of what you've done befire.

Trial (full-function) version expires in 30 (or so) days.

Thank you,
Alexei

Alexei Smirnov said:

NL5 working as "Demo" version if there is no license at all, or if trial/temporary license expired. In Demo, number of components is limited, and not all features are available. However, you can still simulate (without editing) big circuits you've created with the license, so you can see the results of what you've done befire.

Trial (full-function) version expires in 30 (or so) days.

Thank you,
Alexei

Click to expand...

Can you create a (limited) designs from scratch in demo mode, or only simulate?

Dave

Yes, you can do everything what full finction version does, except:
- max. number of components = 20 (may be revised later)
- Transient, AC, and Script Tools are nort available (you may not need it at all)
- "Sweep AC source" method not available (useful for switching circuits analysis).

That's why I said Demo is quite good for students/novices, don't need to buy the license.

Thanks,
Alexei.

Alexei Smirnov said:

Yes, you can do everything what full finction version does, except:
- max. number of components = 20 (may be revised later)
- Transient, AC, and Script Tools are nort available (you may not need it at all)
- "Sweep AC source" method not available (useful for switching circuits analysis).

That's why I said Demo is quite good for students/novices, don't need to buy the license.

Thanks,
Alexei.

Click to expand...

Seems a fair balance. Thanks for the information.

Dave

I always use circuits-cloud

http://circuits-cloud.com

I 'd like to recommend a new free online electronic circuit design tool.
　　There are several free EDA tools around and some excellent FOSS tools such as KiCad and gEDA but the reason I thought people might be interested in this one, EasyEDA, is because it has a few twists to it.

　　i) it's web based so, with nothing except a bit of javascript to install, it can be used by Linux, Mac and Windows users and - if they have a big enough screen - Android and iOS users too;

　　ii) work can be shared and - with a bit of agreement on who saves what, when via a 3rd party instant messaging service - it supports collaboration;

　　iii) it has some pretty impressive import and export options such as importing Altium, Eagle and LTspice files and exporting spice netlists and svg, png and pdf files for documentation. It also uses open standard JSON format files internally so it's easy to do some quite whizzy things just using a text editor;

　　iv) all use of the tool is free even to the point where the user can download PCB Gerbers and send them off to any PCB supplier;

　　v) it also offers a low cost PCB service: PCBs can be ordered directly from within the tool (this seems to be the way the money is made to keep the whole thing afloat);

　　vi) it can even be used without registering with files being saved in an Anonymous mode that works a bit like pastebin where files can be retrieved and shared just by their urls.

　　There are lots of examples on the site and a useful tutorial.https://easyeda.com/Doc/Tutorial/it's easy to drive .

Alexei Smirnov said:

I'd like to suggest my "baby", NL5 (http://nl5.sidelinesoft.com). Just released for public. Free with some limitations, however might be enough for many tasks. My colleagues already switched from Tina and LTSpice.

Click to expand...

Interesting simulator that uses "ideal" components, so it simulates faster than a Spice based simulator without the convergence problems common to Spice.
But it also apparently doesn't handle "real" component models so would not be useful to simulate the Maxim chips the OP wants to use.
I'll stick with LTspice.