Hi,
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. There doesn't seem to be anything wrong with the syntax, hence I tend to believe there is something wrong with the model parameters. I've contacted Linear Systems a while ago, but of course no answer ...
Regards, Klaus
"Klaus Bahner" schrieb im Newsbeitrag news:e83ett$aup$ snipped-for-privacy@news.net.uni-c.dk...
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?
Best regards, Helmut
wrong with the model parameters. I've contacted
You should be checking with Vishay (was Siliconix).
My Intusoft spice has models for sd210 through sd215. Without looking at them all, I see the capacitance varies between types, which is not supported by the datasheets.
.MODEL SD210DE NMOS Level=1 CBD=4.65P CBS=5.58P CGBO=20.6N
.MODEL SD215DE NMOS Level=1 CBD=8.08P CBS=9.7P CGBO=20.6N
I have not evaluated these models. In my experience, if you want to use a MOSFET model for linear work, you have to first vet it against bench measurements, and be prepared to make substantial changes.
results at least when used in OrCAD PSPICE.
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
results at least when used in OrCAD PSPICE.
From where can I download the models?
...Jim Thompson
To be specific, from the zip archive I've used the file LIS_PSPICE.LIB.
Klaus
results at least when used in OrCAD PSPICE.
I duplicated your result.
L=0.5u W=889u is NOT a large device.
What/where are the specs/data-sheet for the real device?
I note that the library specifies VGSmax = +2.5V
...Jim Thompson
results at least when used in OrCAD PSPICE.
voltage, doesn't switch the Fet completely on. In
corresponding to an on resistance in the order of 20k,
:-)
Hello Klaus,
You have to specify the size W and L depending on what FET you want. Then you will get for the SD210DE about Id=11.9mA @ Vgs=2.5V, Vds=5V. The Rds_on is only 10 Ohm with Vgs=10V, but the model is only specified for Vgs up to 2.5V.
Best regards, Helmut
***** MODEL NAMES: ***** ***** SD210DE: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=20V VGSmax=2.5V VBSmax=-2V ***** ***** ***** ***** SD214DE: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=12V VGSmax=2.5V VBSmax=-2V ***** ***** ***** ***** SD5400: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=20V VGSmax=3.5V VBSmax=-2V ***** ***** ***** ***** SD5400CY: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=12V VGSmax=3.5V VBSmax=-2V ***** ***** ***** ***** SST211: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=30V VGSmax=2.5V VBSmax=-2V ***** ***** ***** ***** SST213: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=10V VGSmax=3.5V VBSmax=-2V ***** ***** ***** ***** SST215: DMOS device model W=889um L=0.5um T=27C. ***** ***** BIAS RANGE: VDSmax=20V VGSmax=3.5V VBSmax=-2V ***** ***** *****
results at least when used in OrCAD PSPICE.
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
Those models are Level = 1, which suck the big lemon.
Fortunately Klaus cites models that use PSpice Level = 7, same as HSpice Level = 49, and don't require the "Win-fix" ;-)
...Jim Thompson
"Jim Thompson" schrieb im Newsbeitrag news: snipped-for-privacy@4ax.com...
Hello Jim,
The model given by Win has given a "correct" Rds_on of about
40 Ohms for Vgs=10V. So this model is much better suited for switched applications than the model from Linear Systems.Best regards, Helmut
Thanks Jim and Helmut,
I will try that. (Hope I can figure out how to make the necessary changes in OrCAD's model editor ...)
Klaus
Helmut Sennewald wrote:
news:e83h4s$b7r$ snipped-for-privacy@news.net.uni-c.dk...
results at least when used in OrCAD PSPICE.
voltage, doesn't switch the Fet completely on. In
corresponding to an on resistance in the order of 20k,
:-)
Newsbeitrag
I haven't seen the data sheet, but the library says VGSmax = +2.5V, NOT +10V. I simulated at VGS = +2.5V, thus my slightly higher predicted slope.
As for a Level = 1 model being "better suited" than a Level = 7, ROTFLMAO ;-) Even Win admits the Level = 1 model needs a patch.
Saying a Level = 1 model is "better suited", is like saying a Model-T can outrun my Q45 ;-)
...Jim Thompson
I did this already, but couldn't find any models on Vishay/Siliconix' site. By the way, it seems as if Linear Systems has acquired the DMOS line from Vishay/Siliconix. Although Vishay still lists these devices on their homepage, they seem not to make them any longer (Haven't yet got an authorative answer from my distributor, though). Then there is a company called Calogic, which also offers them, but it could be that these devices will be harder to get.
Are there any alternatives out there, i.e. other small signal, high speed, low leakage, lateral MOSFETs without gate protection diodes?
Klaus
The datasheet says VGSmax +/- 40V! Hence, in general the 2.5V of the model seem to be a limitation, although in my case it's fine, since I anyway want to use the smallest possible gate voltage swing to minimize charge injection.
Klaus
Hello Jim,
That's usually when I trudge over to the lab and fire one up. In analog apps that include fast switching the "not so known" effects of surrounding pulse transformers and stuff like that are hard to simulate.
Put that 1100HP engine in there plus some Formula-1 rear tires and it might just do that ;-)
Hello Klaus,
Don't know what you want to do with them but check out TV tuner FETs such as the BF998. Many of the do have diodes but the capacitances and low.
SD stuff has become harder to buy and some of it like my favorite SD5400 arrays have become expensive so I am not using them anymore.
The machine shop operator was very cordial and bought the engine back. Duane had been one of his best customers and had paid for the engine even though he knew he was near death.
...Jim Thompson
Hello Jim,
That was very nice of him. If they don't part out the engine maybe they could let you know where it went so you could see it in action.
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