Breaking News
Comments
Newest First | Oldest First | Threaded View
<<   <   Page 2 / 3   >   >>
jeff99999
User Rank
Rookie
TI's WEBENCH Designer for Circuit Synthesis and Simulation
jeff99999   8/22/2013 1:46:06 PM
NO RATINGS
  Have you considered TI's WEBENCH Designer for the analog category?  This is a free on line circuit design tool which includes design synthesis, component selection and Spice simulation.  It also has thermal simulation and the ability to download the design into popular CAD tools.  You can get to it at http://www.ti.com/webench.

Sanjib.A
User Rank
CEO
Re: By far the best
Sanjib.A   8/22/2013 12:28:13 PM
NO RATINGS
Thank you for the advice. True...if I have lots of time, usually which is not the case, then a thorough investigation about the models would be possible. In general I tend to simulate to check the concept would or would not work. After ordering the prototype board and before those arrive, the time could be utilized for detailed simulation to be prepared for the mods on prototype...to avoid surprises and frustration :)

Hughston
User Rank
CEO
Re: iCircuit
Hughston   8/22/2013 12:23:36 PM
NO RATINGS
There is a glaring omission here.  You assume nobody wants to use free software to check their PCB? I check things such as trace impedance, trace differential impedance, trace fusing current, trace dc resistance, resistance increase with temperature, estimate power distribution impedance, via current carrying capacity, via impedance and other things. Analog engineers look at their PCB characteristics too. I use Saturn and Ultracad freeware for this but we have an in house tool for traces impedances.

Is there a freeware equivalent of Hyperlynx, or would that be asking too much?

Hughston
User Rank
CEO
Re: By far the best
Hughston   8/22/2013 12:06:12 PM
NO RATINGS
You don't always need the model. You might only care about the component tolerance. It depends upon the level of accuracy you are seeking. You can also use a spreadsheet for some calculations. Sometimes that's easier than SPICE.  If you have a lot of unknows in you system, then should you spend a lot of time on the models?

Hughston
User Rank
CEO
Re: By far the best
Hughston   8/22/2013 11:58:21 AM
NO RATINGS
When using discrete parts in LTSPICE, look at the models. They are often not the real thing. Add the model card and put the real models in if you want better results. Or make your own model.

mike_m
User Rank
Manager
Re: By far the best
mike_m   8/20/2013 6:40:39 PM
NO RATINGS
Without some good test equipment all the modelling software in the world is useless if you can't prove your designs.

For free software: An old copy of ansoft serenade RF designer whichwas bundled with a copy of an antenna text book from the ARRL, LTspice and the excellent free antenna modelling program 4NEC2.

 

Hardware: This along with a Bird RF power meter and slugs, na HP465 precision RF power meter/with head and suitable attenuators, an old analog TEX 465 scope, a HP8558 spectrum analyzer, a HP8640 RF generator with built in freq counter and high power option and an MFJ antenna analyzer along with the solder iron mentioned previously by another individual is all I need for anything from HIGH power RF amplifiers, large multi-element external antennas to small etched internal antenna designs.

dick_myers
User Rank
Rookie
Re: Verilog Simulation
dick_myers   8/19/2013 1:24:32 PM
NO RATINGS
I use LTSpice for analog simulation and Icarus Verilog coupled with GTKWave for digital simulation.  GTKWave is a top quality waveform viewer, and can compete in useability and features with the best commercial tools. 

Icarus Verilog is a very complete and stable free Verilog simulator.  It's a bit slow for large projects that require long time simulations, but totally adequate for many projects. 

Another free simulator that I've got a lot of mileage with is the Verilator (Perl program), with turns synthesizeable Verilog into C++.  If you have the need for speed, this tool will outperform the even the most expensive commercial simulator.  Using the C++ model of the digital circuit that is output by the Verilator, you can model the external circuitry in C or C++.  You can even make a DLL out of the model + behavior circuitry and call it with a GUI, scripting language, or whatever. 

"Verilator should run any system with GCC and Perl. It is developed on 64-bit SuSE 9.3 and other users report success on Redhat Linux, HPUX, Solaris, and Windows NT under Cygwin (C++ only, no SystemC), and Microsoft Visual C++" And, I believe, OSX.

Sheetal.Pandey
User Rank
Manager
Re: What I use
Sheetal.Pandey   8/17/2013 2:50:45 PM
NO RATINGS
Have used pspice simulation. Its good. Its always good to check simulation results before finalizing the gerber for PCB manufacturing.

Clydes_#1
User Rank
Rookie
What I use
Clydes_#1   8/17/2013 11:01:54 AM
NO RATINGS
I use NGSPICE and Kicad for a schematic front end...

 

Yes, as others have said, the simulator is only as good as the models you have.  Google is your friend.

Sanjib.A
User Rank
CEO
Re: By far the best
Sanjib.A   8/17/2013 1:06:32 AM
NO RATINGS
Thanks for the insight! This is a very important point you have mentioned. Using the incorrect models and differences between grounding in the practical scenario vs in simulation causes a lots of differences between simulation vs practical results. Earlier I used to use a ORCAD student's version [it was not free but less costly]...it was good. Currently I use LTSpice a lot and TINA sometimes. I like LTSpice over TINA, but as you have mentioned, I tend not to believe just on the simulation results but also to make a quick bread board circuit and scope to check if it would work as I expect it to.

<<   <   Page 2 / 3   >   >>


Flash Poll
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Rishabh N. Mahajani, High School Senior and Future Engineer

Future Engineers: Don’t 'Trip Up' on Your College Road Trip
Rishabh N. Mahajani, High School Senior and Future Engineer
Post a comment
A future engineer shares his impressions of a recent tour of top schools and offers advice on making the most of the time-honored tradition of the college road trip.

Max Maxfield

Juggling a Cornucopia of Projects
Max Maxfield
2 comments
I feel like I'm juggling a lot of hobby projects at the moment. The problem is that I can't juggle. Actually, that's not strictly true -- I can juggle ten fine china dinner plates, but ...

Larry Desjardin

Engineers Should Study Finance: 5 Reasons Why
Larry Desjardin
28 comments
I'm a big proponent of engineers learning financial basics. Why? Because engineers are making decisions all the time, in multiple ways. Having a good financial understanding guides these ...

Karen Field

July Cartoon Caption Contest: Let's Talk Some Trash
Karen Field
127 comments
Steve Jobs allegedly got his start by dumpster diving with the Computer Club at Homestead High in the early 1970s.

Top Comments of the Week
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)