SPICE Amplifier Simulation

[tschrama]

Hi .....

I'm also very interested in the circuit analysis stuff... so I also simulate a lot in SPICE... and indeed it is very handy .. but I also get some results that just cannot be true... like the push-pull MOSFET simulations .... the complementairy MOSFET devices are just to simple simulated and thus you get results you cannot depend on .... but heee that's a fun game too... to improve your SPICE simulation...:-)

greetings,
Thijs

[ergo]

to:tschrama

Try the 'text' mode (lower left corner). Micro-Cap accepts the standard SPICE models you can get from manufacturers web pages etc. In that way you will get much more precise models. It still ain't same as in real world but should get you much closer.... It helps to have an idea of the theory behind text mode SPICE models and how to configure them in text mode.

I too believe that the simulator is good for evaluation of dc modes and operating point confirmation, but the measurement and most importanly for audio, listening, is still better done in real world.

Ergo

[jduncan]

Great software for doing Chematics AND PCBs is:

Protel SE 99 (www.protel.com)

but be warned, its not cheap!

they do, however, have a fully functional, free, 30 day trial so check it out.

[Silverpike]

Hello all, this is my first post on this forum. I also wanted to say that this is quite possibly one of the coolest places I have found yet for audio.

My question related directly to this thread. alaskanaudio and ergo, you seem to indicate that you have MOSFET models for simulation. Are they lateral MOSFETs? I have looked everywhere, and nobody seems to have any models pre-made for lateral MOSFETs (e.g. 2sj162/2sk1058, buz900p/buz905p, or ecx10p16/ecx10n16).

Worse yet, the MOSFET template I have for my simulator, PSPICE, seems to be geared toward vertical MOSFETs. The template curves aren't the same as the lateral FETs, and I can't seem to change certain params to get the graphs to come out right. So even when I try and make my own models, that doesn't work .

I appreciate that fact that everyone likes their simulators, but I really don't want to change from the one I use now. Can anybody give me some helpful info? Even some documentation would be welcome. I believe it is also possible to code the model in text mode using custom equations, but I really want to avoid that route if at all possible.

FYI, I want this for a specific amp design I am building. This design uses lateral MOSFETs, which, given that this is my first project, I would really rather not deviate from.

Thanks in advance, and I hope everyone is gearing up for an enjoyable holiday season!

[alaskanaudio]

Silverpike,

I received some lateral MOSFET models from Magnatec for the BUZ series that they have and also from Exicon for the devices they market.

They do not list them as being availble on their web sites. Send them a email request and they will send them to you.

John Fassotte
Alaskan Audio

[Mundi]

I'm attempting a Spice simulation of a Leach Amp. However, I am missing models for the following devices. I have been searching the manufacturers' sites and came up empty. Does anyone know where to get them? I am using Simetrix 4.0, which uses Spice3 models or HSPICE .MOD files.

1N4004
1N4148
1N5250B
2N3439
243940
2N5415
2N5416
2N6474
2N6476
MJ15001
MJ15002
MJ15003
MJ15004
MJE15030
MJE15031
MPS8098
MPS8099
MPS8598
MPS8599

[dshortt9]

Users of BUZ900 series MOSFETS

Martinez & Associates,Inc. is pleased to announce that we have been
designated
the sole US distributors for Magnatec's Lateral MOSFET product Line.

We can be reached at:

Martinez & Associates, Inc.
234 Boston Post Road
Wayland, MA 01778
Tel: (508) 358-0131
Fax: (508) 358-2361
email: john@martinezandassoc.cnchost.com

We accept payment by check or VISA, Mastercard, Discover and American
Express credit cards.

We appreciate your interest in Magnatec.

John E. Martinez


I have succesfully purchased BUZ mosfets from them, and obtained spice models.
dshortt9

[Mundi]

I emailed ON Semiconductors and was told they do not supply Spice models for these devices .

[Geoff]

Mundi

Spice models for the MJ15001 and MJ15002 are available from the ONSemi website. For the other MJ/MJE devices you will probably need to use a model from the ONSemi site for a generally similar device. There are several sites on the web with a model for the 1N400x series diodes and the 1N4148. Can't help with the other transistors as I have not had a need to look for these.

Geoff

[traderbam]

I've used Spice a few times and found it helpful to get a rough idea of what is going on in a circuit and specifically to predict what the "ideal" circuit ought to perform like. I use this to compare with what it actually does in order to help track down the causes of the differences. This is very useful.

Like Nelson I would be shy to use it to make really accurate predictions. It's one of those garbage in garbage out situations. The simulation is ignorant of a lot of real-world stuff like lead inductance, stray capacitances, ground line resistances, parasitics and real life psus. You could attempt to include models for all of this but your life would be over before you completed them! I believe some simulators allow you to run Monte Carlo sims on the component parameters.