Forums

2N7000 Spice Model

Started by Jim Thompson June 17, 2014
Last time I tested several 2N7000 Spice models (2005), there was huge
variance between them, and some down-right non-physical behavior.

Has anyone found a better 2N7000 model since then?
		
                                        ...Jim Thompson
-- 
| James E.Thompson                                 |    mens     |
| Analog Innovations                               |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             |
| 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 Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>Last time I tested several 2N7000 Spice models (2005), there was huge >variance between them, and some down-right non-physical behavior. > >Has anyone found a better 2N7000 model since then? > > ...Jim Thompson
The 2N7000/2N7002 parts themselves vary a lot between manufacturers, which is why some of our products specify a specific manufacturer for these parts. What non-physical behavior are you seeing? -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On 17/06/2014 20:02, John Larkin wrote:
> On Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson > <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >> Last time I tested several 2N7000 Spice models (2005), there was huge >> variance between them, and some down-right non-physical behavior. >> >> Has anyone found a better 2N7000 model since then? >> >> ...Jim Thompson > > The 2N7000/2N7002 parts themselves vary a lot between manufacturers, > which is why some of our products specify a specific manufacturer for > these parts. > > What non-physical behavior are you seeing?
I would hope to see some electrical behaviour! -- Mike Perkins Video Solutions Ltd www.videosolutions.ltd.uk
I really don't understand the confusion here. The number 2N7000 is a JEDEC =
registered number, how can there be a variance at all ?=20

I admit I have very little experience with Spice, but JEDEC is JEDEC, no ?=
=20

Going into this "given samples" shit is one thing, but should not be an iss=
ue in design usually. Tolerances are one thing. Current sharing amond MOSFE=
Ts is another, but I doubt anyone has to match a 2N7000 for that purpose.=
=20

In fact I would like to see the scenario in which that would be necessary. =
Well not really in practice, what I mean is for one of the seasoned enginee=
rs around here to actually explain why the $^%#@ #$$&* you owuld have to do=
 that. I thought the thing was a simple switcher, maybe use it linear somet=
imes, but only if you bought a truckload of them. At least that's what I th=
ink.
On Tue, 17 Jun 2014 12:52:12 -0700 (PDT), jurb6006@gmail.com wrote:

>I really don't understand the confusion here. The number 2N7000 is a JEDEC registered number, how can there be a variance at all ?
Typical behaviors could be radically better than the Jedec requirements. Some 2N7002s are ten times as fast as you'd expect from the max rise/fall time specs. Gate leakages can be 8 or so orders of magnitude below the specs. I suspect that one fabbed wafer gets sold as a lot of different part numbers. Nobody really needs 7000+ different transistors. -- John Larkin Highland Technology, Inc jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On Tue, 17 Jun 2014 12:02:40 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:

>On Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>Last time I tested several 2N7000 Spice models (2005), there was huge >>variance between them, and some down-right non-physical behavior. >> >>Has anyone found a better 2N7000 model since then? >> >> ...Jim Thompson > >The 2N7000/2N7002 parts themselves vary a lot between manufacturers, >which is why some of our products specify a specific manufacturer for >these parts. > >What non-physical behavior are you seeing?
All but the Supertex model failed to model ANY behavior below threshold, and the Supertex model had discontinuities in the ID/VDS curve blending... guaranteed to cause simulator convergence issues. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | 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 Tue, 17 Jun 2014 14:15:32 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Tue, 17 Jun 2014 12:02:40 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>Last time I tested several 2N7000 Spice models (2005), there was huge >>>variance between them, and some down-right non-physical behavior. >>> >>>Has anyone found a better 2N7000 model since then? >>> >>> ...Jim Thompson >> >>The 2N7000/2N7002 parts themselves vary a lot between manufacturers, >>which is why some of our products specify a specific manufacturer for >>these parts. >> >>What non-physical behavior are you seeing? > >All but the Supertex model failed to model ANY behavior below >threshold, and the Supertex model had discontinuities in the ID/VDS >curve blending... guaranteed to cause simulator convergence issues. > > ...Jim Thompson
I forgot to reference my old post (4/6/2005)... http://www.analog-innovations.com/SED/Compare2N7000Models.pdf Second page tells it all. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | 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.
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Jim Thompson wrote:
> On Tue, 17 Jun 2014 14:15:32 -0700, Jim Thompson > <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >> On Tue, 17 Jun 2014 12:02:40 -0700, John Larkin >> <jlarkin@highlandtechnology.com> wrote: >> >>> On Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson >>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>> Last time I tested several 2N7000 Spice models (2005), there was huge >>>> variance between them, and some down-right non-physical behavior. >>>> >>>> Has anyone found a better 2N7000 model since then? >>>> >>>> ...Jim Thompson >>> >>> The 2N7000/2N7002 parts themselves vary a lot between manufacturers, >>> which is why some of our products specify a specific manufacturer for >>> these parts. >>> >>> What non-physical behavior are you seeing? >> >> All but the Supertex model failed to model ANY behavior below >> threshold, and the Supertex model had discontinuities in the ID/VDS >> curve blending... guaranteed to cause simulator convergence issues. >> >> ...Jim Thompson > > I forgot to reference my old post (4/6/2005)... > > http://www.analog-innovations.com/SED/Compare2N7000Models.pdf > > Second page tells it all. > > ...Jim Thompson
Fairchild FQD2N100 model attached. --------------070406050500050804060902 Content-Type: text/plain; name="FAIR-FET.LIB" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="FAIR-FET.LIB" ******************************************************************************* * You can read about the added-diode-approach in Steven M. Sandler's * article in Power Electronics Technology, May 2005. ******************************************************************************* * D G S Original model .SUBCKT FQD2N100 d g s Rg g 1 0.04 M1 2 1 3 3 DMOS L=1u W=1u .MODEL DMOS NMOS(VTO=4.66 KP=1.9 LEVEL=3) Cgs 1 3 380p Rd d 4 3.5 Dds 3 4 DDS .MODEL DDS D(BV=1050 M=0.42 CJO=35p VJ=0.12) Dbody 3 d DBODY .MODEL DBODY D(IS=2.8E-13 N=1.00 RS=0.005 EG=1.10 TT=520n) Ra 4 2 3.5 Rs 3 5 0.024 Ls 5 s 2.6n M2 1 8 6 6 INTER E2 8 6 4 1 2 .MODEL INTER NMOS(VTO=0 KP=10 LEVEL=1) CGDMAX 7 4 380p RCGD 7 4 1E7 DGD 6 4 DGD RDGD 4 6 1E7 .MODEL DGD D(M=0.52 CJO=380p VJ=0.12) M3 7 9 1 1 INTER E3 9 1 4 1 -2 .ENDS * And here's my modified model (assuming I found the right file). * Leakage current corrected by raising RDGD to 1G-ohm. * D G S .SUBCKT FQD2N100xG d g s * see Motorola an1043 fig 2 for Cdg model Rg g 1 0.04 Dg 1 11 Dsubthres .MODEL Dsubthres D (N=5.5 IS=0.1n EG=1.1) F1 11 1 VSNS 1 M1 2 11 3 3 DMOS L=1u W=1u .MODEL DMOS NMOS(VTO=2.0 KP=1.9 LEVEL=3) Cgs 1 3 1p Rd d 4 3.5 Dds 15 4 DDS .MODEL DDS D(BV=1050 M=0.42 CJO=35p VJ=0.12) Dbody 15 d DBODY .MODEL DBODY D(IS=2.8E-13 N=1.00 RS=0.005 EG=1.10 TT=520n) Ra 4 2 3.5 VSNS 3 15 Ciss 1 15 380p Rs 15 5 0.024 Ls 5 s 2.6n M2 1 8 6 6 INTER E2 8 6 4 1 2 .MODEL INTER NMOS(VTO=0 KP=10 LEVEL=1) CGDMAX 7 4 380p RCGD 7 4 1E9 DGD 6 4 DGD RDGD 4 6 1E9 .MODEL DGD D(M=0.52 CJO=380p VJ=0.12) M3 7 9 1 1 INTER E3 9 1 4 1 -2 .ENDS --------------070406050500050804060902--
On Tue, 17 Jun 2014 14:23:41 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Tue, 17 Jun 2014 14:15:32 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Tue, 17 Jun 2014 12:02:40 -0700, John Larkin >><jlarkin@highlandtechnology.com> wrote: >> >>>On Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>Last time I tested several 2N7000 Spice models (2005), there was huge >>>>variance between them, and some down-right non-physical behavior. >>>> >>>>Has anyone found a better 2N7000 model since then? >>>> >>>> ...Jim Thompson >>> >>>The 2N7000/2N7002 parts themselves vary a lot between manufacturers, >>>which is why some of our products specify a specific manufacturer for >>>these parts. >>> >>>What non-physical behavior are you seeing? >> >>All but the Supertex model failed to model ANY behavior below >>threshold, and the Supertex model had discontinuities in the ID/VDS >>curve blending... guaranteed to cause simulator convergence issues. >> >> ...Jim Thompson > >I forgot to reference my old post (4/6/2005)... > >http://www.analog-innovations.com/SED/Compare2N7000Models.pdf > >Second page tells it all. > > ...Jim Thompson
If you're actually designing boards with 2N7000s, any of those curves is about as good as any other. Real-life parts will be all over the map. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
On Tue, 17 Jun 2014 19:44:42 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

>On Tue, 17 Jun 2014 14:23:41 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Tue, 17 Jun 2014 14:15:32 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Tue, 17 Jun 2014 12:02:40 -0700, John Larkin >>><jlarkin@highlandtechnology.com> wrote: >>> >>>>On Tue, 17 Jun 2014 09:38:18 -0700, Jim Thompson >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>>Last time I tested several 2N7000 Spice models (2005), there was huge >>>>>variance between them, and some down-right non-physical behavior. >>>>> >>>>>Has anyone found a better 2N7000 model since then? >>>>> >>>>> ...Jim Thompson >>>> >>>>The 2N7000/2N7002 parts themselves vary a lot between manufacturers, >>>>which is why some of our products specify a specific manufacturer for >>>>these parts. >>>> >>>>What non-physical behavior are you seeing? >>> >>>All but the Supertex model failed to model ANY behavior below >>>threshold, and the Supertex model had discontinuities in the ID/VDS >>>curve blending... guaranteed to cause simulator convergence issues. >>> >>> ...Jim Thompson >> >>I forgot to reference my old post (4/6/2005)... >> >>http://www.analog-innovations.com/SED/Compare2N7000Models.pdf >> >>Second page tells it all. >> >> ...Jim Thompson > >If you're actually designing boards with 2N7000s, any of those curves is about >as good as any other. Real-life parts will be all over the map.
You didn't notice the discontinuities? ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | 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.