Want schematic capture and simulation software

[Joey]

I want to do some analog design and board layout for hobby purposes and am looking for a good set of software tools for schematic capture, SPICE simulation, and board layout. As far as schematic capture and SPICE simulation are concerned, I have tried out the Multisim demo version, Tina-TI, and LTspice. I also downloaded a freeware version of the Eagle board layout program but haven't tried it yet.

The free versions of the SPICE simulation packages listed above have very nice graphical front ends and are pretty easy to use. However, they have some frustrating limitations. Multisim (demo version) has a low circuit element count limit and the only supported IC's are from Analog Devices. Tina-TI removed their circuit element count limit in version 7 but the only supported IC's are from TI. LTspice only supports Linear's devices. I want to be able to use some op-amps from Analog Devices, regulator ICs and some special function IC's from Linear, and possibly some TI parts, all in the same circuit design and simulation. The demo software packages don't appear to support SPICE model import and assignment to a schematic symbol.

I want to be able to import SPICE models from different manufacturers and incorporate them as schematic symbols. I would also like to be able to inject signals into a simulation from files that I create a priori and store on disk (think of it as a file-based arbitrary waveform generator capability). The price of the non-demo Multisim packages are beyond my budget, especially when the yearly maintenance cost is factored in. I don't think LTspice is available in anything but a demo version. I'm thinking about purchasing DesignSoft's TINA 8.0 Design Suite Classic Edition, using the upgrade option from Tina-TI to save money. I can't quite afford the Design Suite Industrial version right now but intend to upgrade later. I believe that with the Classic Edition I will be able to import SPICE models and create and edit my own schematic symbols for them. The Design Suite comes with an integrated board layout software package. The feature missing from the Classic Edition (but present in the Industrial version) that I will eventually want is the ability to inject signals from data files.

What SPICE simulation and board layout software packages do people on this forum employ for their personal use? What do you think of TINA? Am I making a good choice? Can I really import SPICE models and make schematic symbols for them in the Classic Edition? Can circuits designed in TINA-TI be imported into the Classic Edition or is that only true for the Industrial version?

Joey

 

[Anonymous]

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[lcyclist]

Actually, LTspice will let you use other vendor's models. Third party supplied models are usually subcircuits (.SUBCKT) or models (.MODEL) format and LTspice can understand those as netlist or create symbols that encapsulate the models.

It is only schematic/simulator but it is a full featured spice program and it is free. And it is the only free spice engine with the best convergence (ie. switchers and switched capacitor circuits-- I tried it with my own circuits and has the capacity/accuracy to rival what we use at work --Cadence Spectre/Synopsis-- multi million software for IC design).
I think LT actually uses this for their IC design. The interface is outdated, but that's just the surface; you can use the spice engine to simulate your circuit created with another schematic capture when you create a netlist.

See http://tech.groups.yahoo.com/group/LTspice/

lcyclist

 

[Joey]

I spent several hours yesterday working with the Eagle v5.6.0 freeware version and really like it. It is great for integrated schematic capture and board layout. However, it does not appear to do SPICE simulation. I went through the process of creating a library and adding a part using a tutorial I found on the instructables.com site. I was able to create a new part by defining a schematic symbol and package layout but there did not appear to be any way to import and assign a device SPICE model to the part. I think I need a separate SPICE simulator.

Here is what I have looked at so far:
(a) Multisim -- freeware version has nice graphical interface but unacceptable limitations. Non-freeware versions are cost prohibitive for me to purchase and yearly maintenance fees make it even less affordable.

(b) Tina-TI -- latest freeware version does not limit complexity of schematic, but there is no apparent way to add 3rd party devices to a circuit. Graphical interface is pretty good. I was able to create a schematic and perform simulation fairly easily. Non-freeware versions (e.g. Tina Classic, Tina Industrial) not cheap but affordable, and no forced yearly maintenance fees. Optional design suite version includes board layout for slightly higher cost.

(c) LTspice -- freeware version only. Graphical interface seems a bit awkward. Simulation accuracy is reportedly very good. I would use this simulator for every circuit if it had all the features I need, but I'm not sure that it does.


I tried to use LTspice for SPICE simulation but I can't figure out how to do the following:
(1) I want to be able to import some Analog Devices opamps and place them in a schematic in LTspice and then run a simulation. I am able to load .cir files from the manufacturer for individual devices but I don't know how to add them into a circuit.

(2) I want to be able to export a circuit captured in LTspice to Eagle for board layout. Is this done by exporting a netlist? LTspice can export netlists in many formats. Are any of them compatible with Eagle?

If I am unable to do these things in LTspice, I may be forced to spend some coin and go with the TINA Design Suite. LTspice has a reputation for accurate simulation. How good is TINA v8? Has anyone used Tina Design Suite's board layout capability?

Joey

 

[Anonymous]

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[Joey]

The B2 spice ordering page at Beige Bag software is very confusing.

Can all versions of B2 spice v5 export to Eagle?

Can B2 Spice v5 export to all versions of Eagle (including freeware version)?

What is the difference between B2 Spice A/D v5 and B2 Spice v5? The A/D nomenclature on the ordering page only appears when B2 Spice is bundled with an Eagle product.

Are Eagle versions sold by Beige Bag any different than the ones sold by CadSoft? Version-for-version, do they have more parts in their libraries?

What happens when a circuit designed in B2 Spice v5 is exported to Eagle and one or more parts in the schematic don't pre-exist in an Eagle library? Is a part automatically created? Do I need to create a package and symbol for each missing part in advance?

Joey

 

[Anonymous]

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[Joey]

nutsandvolts,

Thanks for the link to their tech page. It gives me some idea of the limitations in moving circuits between B2 Spice and Eagle.

I did send a list of questions to BeigeBag but have not received a reply. I was trying to get the information I needed in time to beat the early July ordering deadline for 20% discount.

Joey