Altium Circuit Simulations - Page 1
Forum section: electronics / general

author: ngkee22
author_rank: Regular Contributor
timestamp: June 04, 2011, 09:00:15 pm
content: How well does Altium perform circuit simulations?

author: EEVblog
author_rank: Unknown
timestamp: June 04, 2011, 11:06:26 pm
content: That's an open question...Well, technically it's a full SPICE compliant simulator, so it is capable of doing very good simulations.But in practice it's a real dog to use and has quirks. Most user I know use something else for simulation.I still much prefer to use CircuitMaker 2000 which it is based on.But now I've moved to LTspice.Dave.

author: thmjpr
author_rank: Regular Contributor
timestamp: June 04, 2011, 11:50:38 pm
content: I agree with dave, although I haven't tried r10 (may or may not be improved):http://products.live.altium.com/#r10/explore/bd-MixedSignalSimulationCheck out the altium wiki for tutorials:http://wiki.altium.com/pages/viewpage.action?pageId=3080273http://wiki.altium.com/display/ADOH/Circuit+SimulationExample circuits can be found in C:\Program Files (x86)\Altium Designer xxxxxxx\Examples\Circuit Simulation\

author: Armin_Balija
author_rank: Regular Contributor
timestamp: June 05, 2011, 02:14:40 am
content: I use NI Multisim..I haven't gotten to try anything besides LTspice and Multisim. What do people think of Multisim?

author: djsb
author_rank: Super Contributor
timestamp: June 05, 2011, 01:25:17 pm
content: The few circuits I've tried to simulate on Multisim have produced weird results compared to the same circuit done on Pspice. I really don't trust it. Pspice is my favourite tool for simulation.

author: Psi
author_rank: Super Contributor
timestamp: June 05, 2011, 01:39:32 pm
content: yeah, multisim is a bit weird like that.Sometimes things just dont work, or you get strange results.

author: ngkee22
author_rank: Regular Contributor
timestamp: June 05, 2011, 07:30:00 pm
content: I used Pspice mostly in College and I used a Cadence simulator in my senior class. Both did everything I needed for college, but since I started looking at Altium, I was curious how well it worked. Altium seems like it works like a CAD program I use for electrical harnesses. I like how the background information can be transferred between stages of development, very similar to the CAD program I use. I don't like constanlty moving information manually back and forth, I prefer as much automation and information sharing as possible to cut down on mistakes. Plus, from what I have seen so far, the 3D layout/View of the PCB in Altium looks the best. I work in a world in between full mechanical and electrical engineering, I make the two fields work together, I am more or less in systems engineering. Some of what I want to do, seems like Altium may be a good choice, but I may need to look else where for a simulator.

author: EEVblog
author_rank: Unknown
timestamp: June 05, 2011, 10:24:21 pm
content: Yes the Altium 3D and system integration is the best out there.Altium vision that you can build a simulation model into every one of components and automatically simulate anything is just bunk though, it doesn't really work in practice.So many who use it are still caught in the old situation of having of having one schematic tweaked just for simulation and another for the real product.Certainly not a reasonnotto buy the package though.Dave.

author: ngkee22
author_rank: Regular Contributor
timestamp: June 06, 2011, 12:17:05 am
content: They told us in my senior design class that Cadence was the best. Once we started using it, we quit building circuits in the lab and relied only on Cadence. But I think it is very expensive, that is why I was looking for another alternative too.

author: Armin_Balija
author_rank: Regular Contributor
timestamp: June 06, 2011, 03:17:25 am
content: I feel like Multisim's UI is really intuitive, clean and crisp. It's a shame that it produces such strange results. What would someone recommend to a student. I don't want to learn a program that won't be widely used. Cadence, Eagle, or Pspice?

author: EEVblog
author_rank: Unknown
timestamp: June 06, 2011, 03:50:18 am
content: Quote from: Armin_Balija on June 06, 2011, 03:17:25 amDon't confuse simulation packages with PCB CAD design packages. Pspice is just simulation, like LTspice.Eagle is essentially a hobby level package, you won't get far in the industry with that experience.Cadence is an expensive high end design tool, good to know, but it really depends on where you live and what market.Altium is one of the most popular mid-range packages.Dave.

author: thmjpr
author_rank: Regular Contributor
timestamp: June 06, 2011, 06:47:44 am
content: Quote from: Mechatrommer on June 05, 2011, 11:43:15 pmHe mentioned two:https://www.eevblog.com/forum/index.php?topic=3647.msg48616#msg48616http://www.linear.com/designtools/software/http://my.ece.ucsb.edu/bobsclass/2C/Simulation/circuit_maker.htm

author: EEVblog
author_rank: Unknown
timestamp: June 06, 2011, 07:55:40 am
content: LTspice is free, pretty easy to use, and is professional level, and now gaining vast popularity and reputation.You can't go wrong with using that.Dave.

author: jahonen
author_rank: Super Contributor
timestamp: June 06, 2011, 01:44:45 pm
content: Quote from: Mechatrommer on June 06, 2011, 09:42:00 amI use non-LTC parts regularly with LTSpice, you just have to a) include the spice model file into the schematic by using .include-directive, or by just copy-pasting the subcircuit directly in the schematic (practical if the model is not very long) b) have pin-order-matching symbol for the subcircuit (opamp2.asy works for most opamp spice models)Regards,Janne

author: Unknown
author_rank: Unknown
timestamp: June 06, 2011, 07:48:36 pm
content: I am using different simulators if they have the models I am looking for prebuilt. I found Microchip's Mindi handy when using the MCP6272. I tried LTSpice for this occasion but MCP's SPICE model would not work. I find LTSpice 'hacky' and some circuits require small tweaks for the simulator to start iterating. However, it is powerful when mastered.As a side note, for LTSpice models have a look on the LTSpice's Yahoo group.And a classic joke on simulators, when someone asks you what are you working on on the simulator, tell him you are proving the simulator works.

author: Zero999
author_rank: Super Contributor
timestamp: June 06, 2011, 08:56:51 pm
content: I used to use Altuim where I used to work but we used other packages for simulation such as MicroCap and Electronics Workbench.I use LTSpice most of the time, Electronics Workbench every now and then.

author: Bored@Work
author_rank: Super Contributor
timestamp: June 06, 2011, 09:37:56 pm
content: Quote from: Mechatrommer on June 06, 2011, 09:42:00 amIt is described in the build-in help, in the, *drum rolle*, FAQ sectionLTspice supports a lot of PSPICE extensions, making it typically very easy to use third party modes and subcircuits.QuoteWhat simulation? LTspice does all the classic SPICE simulation types. UseSimulate -> Edit Simulationto select the type of simulation and configure it.There are IMHO things wrong with LTspice, but these aren't. One thing that is wrong with it is that it has a lot of hidden features. There is, for example, since a vew versions a feature for automatic symbol generation. The documentation of this feature is just two sentences, and these aren't very helpful. Granted, the generated symbols don't look great (just boxes with pin numbers), but they spare you a bunch of work in the symbol editor.Other features, especially in those in the graphics display aren't documented at all.QuoteJust another SPICE.My issue with all these SPICE versions is that they do exist ...Every Tom, Dick and Harry (this includes Linear with LTspice), sees the need to come up with on own SPICE. All slightly incompatible and with proprietary extensions. Since decades I wish the industry would form an industry organization for developing and standardizing the SPICE language. That organization should publish a reference implementation, too.Such corporation among competitors works in other areas. Standardization organizations aren't unheard of in the electronics industryBut when it comes to SPICE every company things it is more clever to invest in an own SPICE version and to re-invent the wheel. This is even more unfortunate, because the ancestor of most, if not all of these SPICE versions is the open-source SPICE code from the UCB.

author: ngkee22
author_rank: Regular Contributor
timestamp: June 06, 2011, 10:48:47 pm
content: I looked up Electronics Workbench. It is now Multisim. Looks like National Instruments bought it.

author: Zero999
author_rank: Super Contributor
timestamp: June 08, 2011, 04:56:49 pm
content: One thing which LTSpice doesn't offer is real time simulation but that's not important most of the time.

author: Zero999
author_rank: Super Contributor
timestamp: June 11, 2011, 08:27:57 pm
content: Real-time simulation is also not so accurate as the algorithms will be more optimised for speed than for accuracy.

author: LarryQW
author_rank: Newbie
timestamp: June 15, 2011, 08:10:05 pm
content: Quote from: EEVblog on June 04, 2011, 11:06:26 pmWhat do you mean by "real dog"? Difficult to use, hard to input models, wrong results, lots of bugs,...?

author: hans
author_rank: Super Contributor
timestamp: June 19, 2011, 09:18:22 am
content: I guess he means by that you circuits requires adjusting before it can simulate. I can recall (I think from here) that you still need to place some SPICE symbols or specific parts to simulate the circuit, and then you can convert it to your PCB schematic.Still though, if you have a good library management (which Altium has, if you work neatly) you can link SPICE model, IBIS files, PCB footprints, schematic symbols, datasheets, ordering info all to 1 part. If there is no messing around getting parts in other programs, that's a bonus.What I am keen to know is how 'accurate' the simulations are. It seems like Multisim is really unreliable and inaccurate, Orcad PSPICE is good but sometimes hard to use and LTSpice works great out of the box for LT parts. How does Altium compare?

author: maxseeley
author_rank: Newbie
timestamp: June 24, 2011, 04:23:45 am
content: Most simulation packages are based on Spice from Berkeley. It is a powerful program but was written with a emphasis on mathematical calculations and not with much attention paid to the user interface or user assistance. The error messages are cryptic and even if a circuit is setup properly from the perspective of a "normal circuit", sometimes you can have real issues getting it to run right. There are a lot of tricks: lowering the error tolerance, shunt resistors at the nodes with very high values, specifying initial conditions for some components, and a couple others you can get the simulations to run. This is where the Altium simulation package could use improvement along with numerous other packages including HSpice 2008 (most recent version I have used) and standard PSpice. For instance, it can be a witch hunt sometimes locating a mistake in your netlist or figuring out why your simulation won't run. Some simulation packages have created solutions or tools to deal with these problems - Cadence Advanced Analysis has auto-convergence, part editors, and a couple other tools. For instance, in Altium if you screw up a pin number on a schematic you are screwed and you have to go through your netlist part by part and figure out what the issue is.

author: wolfrum
author_rank: Newbie
timestamp: June 27, 2011, 07:20:36 pm
content: Quote from: ngkee22 on June 04, 2011, 09:00:15 pmProteus is the best one i ever used multisim doesnot have parts!

author: lot2learn
author_rank: Newbie
timestamp: June 30, 2011, 11:08:39 pm
content: Labcenter Proteus seems a good simulator it actually shows you the hard ware in action in real time ;-)

author: gregariz
author_rank: Frequent Contributor
timestamp: July 01, 2011, 01:30:55 am
content: 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.

author: poorchava
author_rank: Super Contributor
timestamp: March 20, 2013, 09:57:39 am
content: +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.