Re: SD21x spice model?

On Fri, 30 Jun 2006 09:21:13 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@xxxxxxxxxxxxxxx> wrote:

On Fri, 30 Jun 2006 17:48:44 +0200, Klaus Bahner
<Klaus.Bahner@xxxxxxxx> wrote:

Helmut Sennewald wrote:

Does anyone have spice models for the SD210/SD214 DMOS Fets?
I've found the models from Linear Systems, but they produce clearly wrong results at least when used in OrCAD PSPICE.



Hello Klaus,

Every Spice model is an approximation for typical parameters of a device.
What's not correctly simulated?

Well, it's not just an approximation thing. Even applying 20V as
gate-source voltage, doesn't switch the Fet completely on. In this case
the model just creates a drain current of about 600uA (@Vds ~13V)
corresponding to an on resistance in the order of 20k, although it
should be only 45 Ohms max.

Wouldn't call this just the usual difference between modelled and real
circuit :-)


Cheers,
Klaus

I duplicated your result.

L=0.5u W=889u is NOT a large device.

What/where are the specs/data-*** for the real device?

I note that the library specifies VGSmax = +2.5V

...Jim Thompson

OK, I found the problem. The bare model is not SIZED.

You need to create a part such that its template is...

MN1 %d %g %s %b SD210 L=0.5u W=889u <<<<

I then get ID = 12mA at VGS = +2.5V, VDS = +2V

And the slope near the origin is 52.6 ohms.

...Jim Thompson
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