On Thu, 25 Nov 2010 11:31:07 -0800, Fred Abse
<excretatauris@invalid.invalid> wrote:

>On Wed, 24 Nov 2010 13:09:18 -0700, Jim Thompson wrote:
>
>> Here you go...
>> 
>> http://analog-innovations.com/SED/Compare2N7000Models.pdf
>> 
>> The Supertex model is fairly good, though not perfect, note the "kink".
>
>Thanks. (though it was Michael Robinson who originally asked).
>
>The Supertex model certainly looks better than the rest.
>
>When I get the opportunity, I shall have to curvetrace a real 7000.

Do you have a curve tracer than can output numerical data to a file?

If so, send to me and I'll try my hand at fitting it.
		
                                        ...Jim Thompson
-- 
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
I love to cook with wine.     Sometimes I even put it in the food.

On Wed, 24 Nov 2010 13:09:18 -0700, Jim Thompson wrote:

> Here you go...
> 
> http://analog-innovations.com/SED/Compare2N7000Models.pdf
> 
> The Supertex model is fairly good, though not perfect, note the "kink".

Thanks. (though it was Michael Robinson who originally asked).

The Supertex model certainly looks better than the rest.

When I get the opportunity, I shall have to curvetrace a real 7000.

-- 
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

On Wed, 24 Nov 2010 13:09:18 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Wed, 24 Nov 2010 10:29:25 -0700, Jim Thompson
><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:
>
>>On Wed, 24 Nov 2010 09:22:57 -0800, Fred Abse
>><excretatauris@invalid.invalid> wrote:
>>
>>>On Sun, 07 Nov 2010 09:50:21 -0700, Jim Thompson wrote:
>>>
>>>> On Sun, 07 Nov 2010 08:25:50 -0800, Fred Abse
>>>> <excretatauris@invalid.invalid> wrote:
>>>> 
>>>>>LTSpice support seven different MOSFET models.
>>>>>
>>>>>Your best plan is to read the appropriate section of the manual, then, if
>>>>>necessary, look up the references cited there.
>>>>>
>>>>>IME, mosfet models are a minefield. There was an old thread in here where
>>>>>Jim Thompson and Winfield Hill discussed this very subject in detail, in
>>>>>an attempt to model low level behavior. It got very involved. There may be
>>>>>some material relating to this on Jim's website.
>>>>>
>>>>>Gamma is supprted in the level 1 through level 3 models, BTW.
>>>> 
>>>> ALL levels of CMOS models attempt (fairly well) to model "body effect"
>>>> 
>>>> The inaccuracies happen at "sub-threshold".
>>>> 
>>>> PSpice has a Level=7 model (BSIM3v3) that works well.  And I'm sure
>>>> LTspice has an equivalent.
>>>> 
>>>> The problem is that discrete device manufacturers provide only lower
>>>> level models, typically Level=3.
>>>> 
>>>> I do vaguely recall showing that one could fit a Level=7 model to a
>>>> 2N7002 device.
>>>> 
>>>> I keep my "Sent" directory trimmed at 2 years, so I can't find the
>>>> pertinent prior posts.
>>>> 
>>>> Perhaps someone can find them via GoogleGroups?
>>>> 		
>>>
>>>
>>>Trawling around here for something unrelated, I found this, apparently
>>>originating from Win Hill, dated march 2005:
>>>
>>>.SUBCKT 2N7000/PLP 1 2 3
>>>Cgs  2 3 12.3E-12
>>>Cgd1 2 4 27.4E-12
>>>Cgd2 1 4 6E-12
>>>M1 1 2 3 3 MOST1
>>>M2 4 2 1 3 MOST2
>>>D1 3 1 Dbody
>>>.MODEL MOST1 NMOS(Level=3 Kp=20.78u W=9.7m L=2u Rs=20m Vto=2 Rd=1.186)
>>>.MODEL MOST2 NMOS(VTO=-4.73 Kp=20.78u W=9.7m L=2u Rs=20m)
>>>.MODEL Dbody D(Is=125f N=1.023 Rs=1.281 Ikf=18.01 Cjo=46.3p M=.3423
>>>+            Vj=.4519 Bv=60 Ibv=10u Tt=161.6n)
>>>.ENDS
>>
>>I did find a simulation comparison on EIGHT different 2N7000 models,
>>only a few came close at sub-threshold.
>>
>>I'll look for the PDF's, and post a link.
>>		
>>                                        ...Jim Thompson
>
>Here you go...
>
>http://analog-innovations.com/SED/Compare2N7000Models.pdf
>
>The Supertex model is fairly good, though not perfect, note the
>"kink".
>		
>                                        ...Jim Thompson

When I was searching for this file I ran across an IRF120 test that
shows that even the Level=3 model properly show the gate charge
plateau.

So would could muse if there's a way to take the existing Level=3
stuff and easily convert to Level=7 equivalents, then see what one
needs to twiddle to match sub-threshold.
		
                                        ...Jim Thompson
-- 
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
If Nancy Pelosi gave Obama one of her balls, they'd both have two.

On Wed, 24 Nov 2010 10:29:25 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Wed, 24 Nov 2010 09:22:57 -0800, Fred Abse
><excretatauris@invalid.invalid> wrote:
>
>>On Sun, 07 Nov 2010 09:50:21 -0700, Jim Thompson wrote:
>>
>>> On Sun, 07 Nov 2010 08:25:50 -0800, Fred Abse
>>> <excretatauris@invalid.invalid> wrote:
>>> 
>>>>LTSpice support seven different MOSFET models.
>>>>
>>>>Your best plan is to read the appropriate section of the manual, then, if
>>>>necessary, look up the references cited there.
>>>>
>>>>IME, mosfet models are a minefield. There was an old thread in here where
>>>>Jim Thompson and Winfield Hill discussed this very subject in detail, in
>>>>an attempt to model low level behavior. It got very involved. There may be
>>>>some material relating to this on Jim's website.
>>>>
>>>>Gamma is supprted in the level 1 through level 3 models, BTW.
>>> 
>>> ALL levels of CMOS models attempt (fairly well) to model "body effect"
>>> 
>>> The inaccuracies happen at "sub-threshold".
>>> 
>>> PSpice has a Level=7 model (BSIM3v3) that works well.  And I'm sure
>>> LTspice has an equivalent.
>>> 
>>> The problem is that discrete device manufacturers provide only lower
>>> level models, typically Level=3.
>>> 
>>> I do vaguely recall showing that one could fit a Level=7 model to a
>>> 2N7002 device.
>>> 
>>> I keep my "Sent" directory trimmed at 2 years, so I can't find the
>>> pertinent prior posts.
>>> 
>>> Perhaps someone can find them via GoogleGroups?
>>> 		
>>
>>
>>Trawling around here for something unrelated, I found this, apparently
>>originating from Win Hill, dated march 2005:
>>
>>.SUBCKT 2N7000/PLP 1 2 3
>>Cgs  2 3 12.3E-12
>>Cgd1 2 4 27.4E-12
>>Cgd2 1 4 6E-12
>>M1 1 2 3 3 MOST1
>>M2 4 2 1 3 MOST2
>>D1 3 1 Dbody
>>.MODEL MOST1 NMOS(Level=3 Kp=20.78u W=9.7m L=2u Rs=20m Vto=2 Rd=1.186)
>>.MODEL MOST2 NMOS(VTO=-4.73 Kp=20.78u W=9.7m L=2u Rs=20m)
>>.MODEL Dbody D(Is=125f N=1.023 Rs=1.281 Ikf=18.01 Cjo=46.3p M=.3423
>>+            Vj=.4519 Bv=60 Ibv=10u Tt=161.6n)
>>.ENDS
>
>I did find a simulation comparison on EIGHT different 2N7000 models,
>only a few came close at sub-threshold.
>
>I'll look for the PDF's, and post a link.
>		
>                                        ...Jim Thompson

Here you go...

http://analog-innovations.com/SED/Compare2N7000Models.pdf

The Supertex model is fairly good, though not perfect, note the
"kink".
		
                                        ...Jim Thompson
-- 
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
If Nancy Pelosi gave Obama one of her balls, they'd both have two.

On Wed, 24 Nov 2010 09:22:57 -0800, Fred Abse
<excretatauris@invalid.invalid> wrote:

>On Sun, 07 Nov 2010 09:50:21 -0700, Jim Thompson wrote:
>
>> On Sun, 07 Nov 2010 08:25:50 -0800, Fred Abse
>> <excretatauris@invalid.invalid> wrote:
>> 
>>>LTSpice support seven different MOSFET models.
>>>
>>>Your best plan is to read the appropriate section of the manual, then, if
>>>necessary, look up the references cited there.
>>>
>>>IME, mosfet models are a minefield. There was an old thread in here where
>>>Jim Thompson and Winfield Hill discussed this very subject in detail, in
>>>an attempt to model low level behavior. It got very involved. There may be
>>>some material relating to this on Jim's website.
>>>
>>>Gamma is supprted in the level 1 through level 3 models, BTW.
>> 
>> ALL levels of CMOS models attempt (fairly well) to model "body effect"
>> 
>> The inaccuracies happen at "sub-threshold".
>> 
>> PSpice has a Level=7 model (BSIM3v3) that works well.  And I'm sure
>> LTspice has an equivalent.
>> 
>> The problem is that discrete device manufacturers provide only lower
>> level models, typically Level=3.
>> 
>> I do vaguely recall showing that one could fit a Level=7 model to a
>> 2N7002 device.
>> 
>> I keep my "Sent" directory trimmed at 2 years, so I can't find the
>> pertinent prior posts.
>> 
>> Perhaps someone can find them via GoogleGroups?
>> 		
>
>
>Trawling around here for something unrelated, I found this, apparently
>originating from Win Hill, dated march 2005:
>
>.SUBCKT 2N7000/PLP 1 2 3
>Cgs  2 3 12.3E-12
>Cgd1 2 4 27.4E-12
>Cgd2 1 4 6E-12
>M1 1 2 3 3 MOST1
>M2 4 2 1 3 MOST2
>D1 3 1 Dbody
>.MODEL MOST1 NMOS(Level=3 Kp=20.78u W=9.7m L=2u Rs=20m Vto=2 Rd=1.186)
>.MODEL MOST2 NMOS(VTO=-4.73 Kp=20.78u W=9.7m L=2u Rs=20m)
>.MODEL Dbody D(Is=125f N=1.023 Rs=1.281 Ikf=18.01 Cjo=46.3p M=.3423
>+            Vj=.4519 Bv=60 Ibv=10u Tt=161.6n)
>.ENDS

I did find a simulation comparison on EIGHT different 2N7000 models,
only a few came close at sub-threshold.

I'll look for the PDF's, and post a link.
		
                                        ...Jim Thompson
-- 
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
If Nancy Pelosi gave Obama one of her balls, they'd both have two.

On Sun, 07 Nov 2010 09:50:21 -0700, Jim Thompson wrote:

> On Sun, 07 Nov 2010 08:25:50 -0800, Fred Abse
> <excretatauris@invalid.invalid> wrote:
> 
>>LTSpice support seven different MOSFET models.
>>
>>Your best plan is to read the appropriate section of the manual, then, if
>>necessary, look up the references cited there.
>>
>>IME, mosfet models are a minefield. There was an old thread in here where
>>Jim Thompson and Winfield Hill discussed this very subject in detail, in
>>an attempt to model low level behavior. It got very involved. There may be
>>some material relating to this on Jim's website.
>>
>>Gamma is supprted in the level 1 through level 3 models, BTW.
> 
> ALL levels of CMOS models attempt (fairly well) to model "body effect"
> 
> The inaccuracies happen at "sub-threshold".
> 
> PSpice has a Level=7 model (BSIM3v3) that works well.  And I'm sure
> LTspice has an equivalent.
> 
> The problem is that discrete device manufacturers provide only lower
> level models, typically Level=3.
> 
> I do vaguely recall showing that one could fit a Level=7 model to a
> 2N7002 device.
> 
> I keep my "Sent" directory trimmed at 2 years, so I can't find the
> pertinent prior posts.
> 
> Perhaps someone can find them via GoogleGroups?
> 		


Trawling around here for something unrelated, I found this, apparently
originating from Win Hill, dated march 2005:

.SUBCKT 2N7000/PLP 1 2 3
Cgs  2 3 12.3E-12
Cgd1 2 4 27.4E-12
Cgd2 1 4 6E-12
M1 1 2 3 3 MOST1
M2 4 2 1 3 MOST2
D1 3 1 Dbody
.MODEL MOST1 NMOS(Level=3 Kp=20.78u W=9.7m L=2u Rs=20m Vto=2 Rd=1.186)
.MODEL MOST2 NMOS(VTO=-4.73 Kp=20.78u W=9.7m L=2u Rs=20m)
.MODEL Dbody D(Is=125f N=1.023 Rs=1.281 Ikf=18.01 Cjo=46.3p M=.3423
+            Vj=.4519 Bv=60 Ibv=10u Tt=161.6n)
.ENDS


-- 
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

On Sun, 07 Nov 2010 09:50:21 -0700, Jim Thompson wrote:

> On Sun, 07 Nov 2010 08:25:50 -0800, Fred Abse
> <excretatauris@invalid.invalid> wrote:
> 
>>LTSpice support seven different MOSFET models.
>>
>>Your best plan is to read the appropriate section of the manual, then, if
>>necessary, look up the references cited there.
>>
>>IME, mosfet models are a minefield. There was an old thread in here where
>>Jim Thompson and Winfield Hill discussed this very subject in detail, in
>>an attempt to model low level behavior. It got very involved. There may be
>>some material relating to this on Jim's website.
>>
>>Gamma is supprted in the level 1 through level 3 models, BTW.
> 
> ALL levels of CMOS models attempt (fairly well) to model "body effect"
> 
> The inaccuracies happen at "sub-threshold".
> 
> PSpice has a Level=7 model (BSIM3v3) that works well.  And I'm sure
> LTspice has an equivalent.
> 
> The problem is that discrete device manufacturers provide only lower
> level models, typically Level=3.
> 
> I do vaguely recall showing that one could fit a Level=7 model to a
> 2N7002 device.
> 
> I keep my "Sent" directory trimmed at 2 years, so I can't find the
> pertinent prior posts.
> 
> Perhaps someone can find them via GoogleGroups?
> 		

ISTR that some stuff was PDFs posted to a.b.s.e, so they won't have those.
I did save copies for a while, but I'm not interested enough in mosfets to
have kept them indefinitely.

-- 
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Jim Thompson wrote:
>The problem is that discrete device manufacturers
>provide only lower level models, typically Level=3.
>
>I do vaguely recall showing that one could fit a Level=7 model
>to a 2N7002 device.
>
>I keep my "Sent" directory trimmed at 2 years,
>so I can't find the pertinent prior posts.
>Perhaps someone can find them via GoogleGroups?
>
http://groups.google.com/group/sci.electronics.design/search?group=sci.electronics.design&q=2N7000+Level-7+Thompson&qt_g=Search+this+group

On Sun, 07 Nov 2010 08:25:50 -0800, Fred Abse
<excretatauris@invalid.invalid> wrote:

>LTSpice support seven different MOSFET models.
>
>Your best plan is to read the appropriate section of the manual, then, if
>necessary, look up the references cited there.
>
>IME, mosfet models are a minefield. There was an old thread in here where
>Jim Thompson and Winfield Hill discussed this very subject in detail, in
>an attempt to model low level behavior. It got very involved. There may be
>some material relating to this on Jim's website.
>
>Gamma is supprted in the level 1 through level 3 models, BTW.

ALL levels of CMOS models attempt (fairly well) to model "body effect"

The inaccuracies happen at "sub-threshold".

PSpice has a Level=7 model (BSIM3v3) that works well.  And I'm sure
LTspice has an equivalent.

The problem is that discrete device manufacturers provide only lower
level models, typically Level=3.

I do vaguely recall showing that one could fit a Level=7 model to a
2N7002 device.

I keep my "Sent" directory trimmed at 2 years, so I can't find the
pertinent prior posts.

Perhaps someone can find them via GoogleGroups?

                                        ...Jim Thompson
-- 
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

 Ding Dong! The Wicked Old Witch Pelosi is Dead! Hurrah! Hurrah!