Wich SPICE do you use?

[awhiteguy]

Orcad and SwitcherCAD III, the latter is much easier to use.

Does anyone that uses SwitcherCAD know how to add parts like MOSFETS?

[Bricolo]

thanks all

but since I've made several shematics with my orcad pspice demo, and they won't certainly work on another spice based simulator, I'll stay with pspice

I've read (on this board) someone's post, in wich he said he managed to add models to pspice student

Now, I "only" need to know how he did this

[raul_77]

Hi all,

I have forget, some of yours visited the web page of pcb-pool:

www.pcb-pool.com

In the section 'Downloads' yours can see that have a 'pcb-pool version' of Target 3001!.

The only limit is that, the output files are only valid for pcb-pool so, if yours like made your own pcb's, this program don't are usefull.

But the other parts of the program are fully functional: schematic capture and simulation and, as say the web page: totally free, no limits.

If someone need a Spice Simulator, and don't like the limits of the Students versions, of use a illegal copy of a commercial software, this have a professional Spice for Free.

Happy days

Raúl Couto

[Edmond Stuart]

Originally Posted by jackinnj

[snip]
btw, YES, there is an opto-coupler SPICE model, something long sought after -- it's on the PDF for the Agilent HCNR-200 device. Why's an optocoupler spice model important? -- if you amplify the output (since photodiodes have large capacitance) you will almost certainly put the device into oscillation if not properly compensated. The HCNR-200 is an analog opto-coupler. Very helpful in noisy environments.

Hi jackinnj,

Did you ever use the HCNR-200 model? I'm asking this because (in my hands) it doesn't work. The X-fer ratio (K1) is way too low.
What make me suspicious is a beta of only 10m in the transistor model:

* LED/Optical-coupling transistor model
.model QCPL NPN(IS=2.214E-19 BF=10m NF=1.010 IKF=11.00m ISE=1.167P
+ NE=1.737 RB=3.469 VAF=100 TF=1.77U CJE=80P)

When I set BF to 100, the thing does work, but I wonder if it is correct.
Maybe something else is wrong with the model and I should keep BF=10m.
What's your opinion on this?

Cheers,
E.

[jackinnj]

Originally Posted by Edmond Stuart

Hi jackinnj,
Did you ever use the HCNR-200 model?

From figure 16 in the datasheet:



The datasheet for the Siemens IL-300 has a number of good examples.

[Edmond Stuart]

The model is indeed OK. It was me who made a stupid error.
Thanks for reply.

Cheers,
E.

[jackinnj]

The Vishay IL-300 has a higher coupling factor.

[gootee]

Originally Posted by awhiteguy

Orcad and SwitcherCAD III, the latter is much easier to use.

Does anyone that uses SwitcherCAD know how to add parts like MOSFETS?

If you have the model in a text file, you just .include that file with a spice directive somewhere on your schematic.

If you already have an appropriate symbol for the model, then you just plop it onto the schematic, right-click on it, enter X (I think) in the Prefix field and the model's part name in the Value field. (I forget what's necessary and/or allowable etc for the prefix field.)

If in doubt about the pin assignments, right-click on it in the schematic and then click on Open Symbol. Right-clicking on each pin/port will show the "netlist order" number, which must correspond correctly to the numbering in the model file.

If you DON'T already have an appropriate symbol for something, just select Hierarchy and then Create New Symbol. Select Edit then select Add Pin/Port, to add the pins (and number them correctly). Then draw the shapes/lines, etc.

To get the hang of creating and using symbols and hierarchies, you could draw a simple circuit schematic, label the inputs and outputs, and then make a symbol for it (pin LABELS matter more than netlist order, for symbols that represent your own .ASC circuit schematics). Name the symbol with the same base filename as the .asc file. Then you could place that symbol on a schematic, right click and enter X in the Prefix field (pretty sure), and then add other components or symbols around it (if necessary) and run it. If you make a bunch of building-block circuits and make block-like symbols for them, you can draw a circuit that looks more like a block diagram than a schematic and run the thing. It's pretty powerful. And sometimes it's the only way to get everything on the screen in a readable format. Also, it's very quick and easy to burrow down into the hierachy and look at the schematics and plot things from them, etc.

I hope I remembered everything correctly. It's been a while.

Cheers,

Tom

[jackinnj]

Originally Posted by awhiteguy

Does anyone that uses SwitcherCAD know how to add parts like MOSFETS?

To what has already been written, I would suggest that reading the SPICE section of Bob Cordell's book "Designing Audio Power Amplifiers" will help quite a bit. He describes many of the spice parameters and how you can make better models from the datasheets, or from your own observations.