Altium Circuit Simulations

[gregariz]

I find it depends on what you are doing. I really only use it for discrete analog design so bear in mind when reading the following.. I've used pSpice since the first Schematic Capture version in about 93 or 94 but I feel that Cadence/Orcad slowly destroyed its ease of use in the last 15 years. As a result I have often gone back to pre Cadence - Microsim v8 (search the web you'll find it) - I still think it blows most of the modern packages out of the water even though its at least a dozen years old, but of course its no longer supported and the models are not there for alot of stuff these days so I had been searching for a few years now until...

I had been using the free QUC's for a time and it was ok but I don't really like its interface or its speed - but hey its free so the price is right.

Nowadays, I've moved away from both of the above and use 5spice instead. It's really easy - to the point where I prefer it now over pSpice and that is saying alot as I've probably tried over a dozen different spices (sorry but the user experience on most of them suck so badly it makes me wonder if the designers have been smoking doobies). 5 Spice accepts standard spice models so I've never had a problem just going into Fairchild or whatever discrete semi maker and downloading their device model and using it.

Now having said that - I'm not really a fan of any spice really. I fall into line behind people like Bob Pease who hated it, although I don't really gop that far. The trouble with Spice is that the models are essentially ideal and as a result they LIE to you. I've modeled simple BJT amplifiers where I've had 800Volt outputs when powered by a 9V battery. But thats just one of many LIES, so unless I've done a pen and paper design and then hacked the model parameters to agree with that and a bread boarded version I'm just very sceptical of the output. So .. I'm afraid I use it mostly to verify these days. I don't trust if for an untested design as a general rule. Sometimes I use it just to mess with an idea to see what basic behaviour is - ie what type of feedback, maybe give me a feel for how touchy some circuit is.

Now digital simulation may be something else - but I've never used it for that, I kind of figure why bother.. thats alot easier anyhow just to breadboard it and play with a logic probe or code.

[poorchava]

+1 to LTSpice.

IMO it presents a perfect balance between capabilities and ease of use. It has great interface with possibility to invoke any commonly used command (yes Novarm, you could learn from LT how to do interface). With some practice you can draw and modify your circuit at a speed of light. It's also quite easy to add new models which was pretty convoluted in pspice for example. And of course it has great community support from Yahoo mailing group.