Altium Circuit Simulations

[ngkee22]

How well does Altium perform circuit simulations?

[EEVblog]

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.

[thmjpr]

I agree with dave, although I haven't tried r10 (may or may not be improved): http://products.live.altium.com/#r10/explore/bd-MixedSignalSimulation

Check out the altium wiki for tutorials:
http://wiki.altium.com/pages/viewpage.action?pageId=3080273
http://wiki.altium.com/display/ADOH/Circuit+Simulation

Example circuits can be found in C:\Program Files (x86)\Altium Designer xxxxxxx\Examples\Circuit Simulation\

[Armin_Balija]

I use NI Multisim..I haven't gotten to try anything besides LTspice and Multisim. What do people think of Multisim?

[djsb]

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.

[Psi]

yeah, multisim is a bit weird like that.
Sometimes things just dont work, or you get strange results.

[ngkee22]

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.

[EEVblog]

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 reason not to buy the package though.

Dave.

[ngkee22]

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.

[Armin_Balija]

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?

[EEVblog]

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?

Don'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.

[thmjpr]

so, is there simulation program that does really work in practice? name of the program please?

He mentioned two: https://www.eevblog.com/forum/index.php?topic=3647.msg48616#msg48616

http://www.linear.com/designtools/software/
http://my.ece.ucsb.edu/bobsclass/2C/Simulation/circuit_maker.htm

[EEVblog]

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.

[jahonen]

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.

the problem is i cannot get all the parts into the circuit in LTSpice, and i dont see anywhere to do spice modeling. and the sim with fix timeline is quite PITA for me. i recently downloaded Tina-TI, i dont know how good its Spice SIM, but for their parts/ic (still limited though) the sim works nice, and i can do SPICE model/part creation, just a matter of finding a good spice code somewhere. and the SIM with virtual dso, fg, signal analyzer, dmm etc make it like we are debugging in real life. any comment about this tina?

I 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

[Alex]

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.

[Zero999]

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.

[Bored@Work]

the problem is i cannot get all the parts into the circuit in LTSpice, and i dont see anywhere to do spice modeling.

It is described in the build-in help, in the, *drum rolle*, FAQ section  LTspice supports a lot of PSPICE extensions, making it typically very easy to use third party modes and subcircuits.

and the sim with fix timeline is quite PITA for me.

What simulation? LTspice does all the classic SPICE simulation types. Use Simulate -> Edit Simulation to 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.

any comment about this tina?

Just 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 industry    But 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.

[ngkee22]

I looked up Electronics Workbench.  It is now Multisim.  Looks like National Instruments bought it.

[Zero999]

One thing which LTSpice doesn't offer is real time simulation but that's not important most of the time.

[Zero999]

Real-time simulation is also not so accurate as the algorithms will be more optimised for speed than for accuracy.

[LarryQW]

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.

What do you mean by "real dog"? Difficult to use, hard to input models, wrong results, lots of bugs,...?

[hans]

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?

[maxseeley]

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.

[wolfrum]

How well does Altium perform circuit simulations?

Proteus is the best one i ever used multisim doesnot have parts!

[lot2learn]

Labcenter Proteus seems a good simulator it actually shows you the hard ware in action in real time ;-)