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For those reading their messages from the web, the formatting on my
last message got badly mangled again. (I wonder how often this
happens?!)

Here is my message again, as plain text:

-----------------------
I hadn't read this particular thread until today.

The schematic currently in the TEMP folder "works" as is. I guess
that means the original poster has commented-out the two offending
lines ".LIB" and ".ENDL", which must have caused error messages
before.

But, some important comments follow.

The circuit simulates, but the drain voltage barely moves ... because
the drain current is much too small (<1mA).

The biggest problem is the missing size parameters for the MOSFET. A
lot of people seem to forget that, and this is one case where it
really matters. MOSFET channels can be made in widely varying sizes
(length/width), with the same process (.MODEL statement), and you need
to tell LTspice what size MOSFET you have for each of them.

Until you do that, this "power" FET has the default wimpy channel size
of 100 microns by 100 microns ... probably not appropriate for a power
MOSFET.

The correct way to use MOSFETs in LTspice (or in any other SPICE), is
to supply each FET on your schematic with length (L) and width (W)
parameters, among others.

Press ctrl-right-click on the MOSFET symbol, and then add:

W=12345u L=67890u

to either the Value or Value2 or SpiceLine or SpiceLine2 line. (Use
the actual width and length, of course.) If you use Value2 or
SpiceLine or SpiceLine2, I recommend checking the box to make it
visible on your schematic. Schematics with MOSFETs *ought* to have
their dimensions shown on the schematic, IMHO.

In this case, the model file even tells you the dimensions to use:

* W = 228740 E-6 m
* L = 3.0 E-6 m
* AD = 228740 E-12 m2

(where 'm' and 'm2' refer to the units meters, and meters squared or
square meters)

So add this to your Value2 line for the component:

W=228740e-6 L=3.0e-6 AD=228740e-12

If you prefer, use 'u' instead of E-6, and 'p' instead of E-12.
Either way, be careful NOT to have any spaces between the mantissa and
the multiplier (exponent).

W=228740u L=3.0u AD=228740p

So what is that extra parameter, AD? Parameters AD and AS are the
areas (in square meters) of the source and drain, and you should
include them if you know what they are. If not, LTspice defaults to
zero. Sanyo/OnSemi tells you what AD ought to be. Use it.

Once you make those changes, you will see the drain voltage behaving
like you probably expected it to.

Other instance-specific parameters include PD, PS, NRD, and NRS. See
the Help file. If you know what they are, use them. This model
apparently doesn't use them.

Two other points:

The model wants you to add a 9 ohm resistor in series with the gate
lead. You used 25 ohms. (Why?) This resistance is internal to the
MOSFET, perhaps between the package pin and the die pad or the gate
metal. If I were you, I'd stick with what they tell you and not
change it. Your schematic says this is a "switching time test
circuit", so its value is probably quite important. If you thought
that resistor was external to the FET (perhaps in the test
equipment?), you would need another resistor for that.

Sanyo also wants you to add a 0.045 ohm resistor between the "bulk"
node and the source pin. In order to do that, you need to use the
4-pin version of the MOSFET symbol, "nmos4" in LTspice
.
Evidently they think it is important enough to include it.

Regards,
Andy

Andy -


Where do you find channel size information? I do not recall that detail on spec sheets.


Jim Wagner
Oregon Research Electronics

I hadn't
read
this particular thread until today.

The schematic currently in the TEMP folder "works" as is. I guess that
means the original poster has commented-out the two offending lines ".LIB"
and ".ENDL", which must have caused error messages before.

But, some important comments follow.

The circuit
simulates
, but the drain voltage barely moves ... because the drain current is much
too small (<1mA).

*
T
he biggest
problem is
the
missing
size parameters for the MOSFET.* A lot of people seem to forget that, and
this is one case where it really matters. MOSFET channels can be made in
widely varying
sizes
(length/width)
, with the same
process (.MODEL statement), and you need to tell LTspice what size MOSFET
you have
for each of them
.

Until you do that, this "power" FET has the default
wimpy
channel size of 100 microns by 100 microns ... probably not appropriate for
a power MOSFET.

The correct way to use
MOSFETs
in LTspice (or in any other SPICE), is to supply each FET on your
schematic with length (L) and width (W) parameters, among others.
P
ress ctrl-right-click on the MOSFET symbol, and then add:

W=12345u L=67890u

to
either
the Value or Value2 or SpiceLine or SpiceLine2 line. (Use the actual width
and length, of course.) If you use Value2 or SpiceLine or SpiceLine2, I
recommend checking the box to make it visible on your schematic.
Schematics with MOSFETs *ought* to have their dimensions shown on the
schematic, IMHO.

In this case, the
model file even tells you the
dimensions to use
:

* W = 228740 E-6 m

* L = 3.0 E-6 m

* AD = 228740 E-12 m2


(where 'm' and 'm2' refer to the units meters, and meters squared or square
meters)

So add this to your Value2 line for the component:

W=228740e-6 L=3.0e-6 AD=228740e-12

If you prefer, use 'u' instead of E-6, and 'p' instead of E-12. Either
way, be careful NOT to have any spaces between the mantissa and the
multiplier (exponent).

W=228740u L=3.0u AD=228740p

So what is
that
extra parameter
,
AD? Parameters AD and AS are the areas (in square meters) of the source
and drain, and you should include them if you know what they are. If not,
LTspice defaults to zero. Sanyo/OnSemi tells you what AD ought to be. Use
it.

Once you make those changes, you will see the drain voltage behaving like
you probably expected it to.

Other
instance
-specific parameters include PD, PS, NRD, and NRS.
See the Help file.
If you know what they are, use them. This model
apparently
doesn't
use
them.

Two other points:

The model wants you to add a 9 ohm resistor in series with the gate lead.
You used 25 ohms. (Why?) This resistance is internal to the MOSFET,
perhaps between the package pin and the die
pad
or the gate metal. If I were you, I'd stick with what they tell you and
not change it. Your schematic says this is a "switching time test
circuit", so its value is probably quite important.
If you thought that resistor was external to the FET (perhaps in the test
equipment?), you would need another resistor for that.

Sanyo
also wants you to add a 0.045 ohm resistor between the "bulk" node and the
source pin. In order to do that, you need to use the 4-pin version of the
MOSFET symbol, "nmos4" in LTspice
.
Evidently they think it is important enough to
include
it
.

Regards,
Andy

Its my experience that ALL oscillators should be constructed of bias
stable amplifiers,
or else theyll have start up issues, even in real life.
Observing this, ive never had op point difficulties.

This was an astable multivibrator, which is very different from the
usual type of oscillator. They work BECAUSE they don't have a stable
operating point (hence the name "astable" = "not stable"). They want,
or need, to change state all the time. They can't stay in either
state. This is perfect for ensuring oscillation.

Real astable multivibrators rarely ever have trouble starting up in real life.

Simulated ones often have problems in SPICE, UNLESS you add the little
bits of magic to help it find an initial operating point, and trick it
into thinking it is stable there. What the .IC statement does is tell
SPICE what the operating point will be, so that it doesn't need to
find the operating point at all. That keeps it happy.

Your observations are OK for most other oscillator types ... which
could be stable but not oscillating.

Andy

Hi All

Its my experience that ALL oscillators should be constructed of bias
stable amplifiers,
or else theyll have start up issues, even in real life.
Observing this, ive never had op point difficulties.

Granted that you can shock excite the non bias stable types, but
that gives me no warm fuzzies as to reliability.

Al D.

--


AC2CL

I do not think there is any thrill that
can go through the human heart like that felt by the inventor as
he sees some creation of the brain unfolding to success...
Such emotions make a man forget food, sleep, friends, love, everything.

- Nikola Tesla

--- In LTspice@..., "cury.joaquin" <cury.joaquin@...> wrote:

Hello, I am trying to use LTspice with the Electric VLSI design. In the Electric ?s tutorial, says that in Electric, I have to go to:

Tools / Simulation (Spice) / Write Spice Deck...

When I am trying to do this, a window appears and says:

Mnmos 0: can ?t find definition of model "n" L=400n W= 2.4u
Select OK to continue the simulation with the default model
or cancel to quit now.

What should I do ?

Thanks.

Hello,

You have a mistake in a SPICE-line.

Please view the netlist and show us the SPICE-line causing
this error message.

View -> Spice Netlist

Best regards,
Helmut

Hello, I am trying to use LTspice with the Electric VLSI design. In the Electric ?s tutorial, says that in Electric, I have to go to:

Tools / Simulation (Spice) / Write Spice Deck...

When I am trying to do this, a window appears and says:

Mnmos 0: can ?t find definition of model "n" L=400n W= 2.4u
Select OK to continue the simulation with the default model or cancel to quit now.

What should I do ?

Thanks.

Thanks Helmut!


?
Met Vriendlijke groeten/ Kind Regards,
Jude Anizoba
Fontys University of applied Science,
Eindhoven,The Netherlands


________________________________
From: Helmut <helmutsennewald@...>
To: LTspice@...
Sent: Thursday, August 8, 2013 4:03 PM
Subject: [LTspice] Re: New Component Creation



?


--- In LTspice@..., jude thad <jukwai3@...> wrote:

Hello All,

I am kind of new to LTspice.
Please I want to know how to create entirely new component symbol in LTspice.
Thanks in advance for your help.

?
?Kind Regards,
Jude Anizoba

Hello Jude,

You could look this video.
LTspice IV: Adding Third-Party Models


There are also many links to tutorials.


Best regards,
Helmut




[Non-text portions of this message have been removed]

Thanks Helmut.


Regards
AbhinavFrom: "Helmut" <helmutsennewald@...>Sent: Wed, 07 Aug 2013 10:33:07 To: LTspice@...: [LTspice] How to plot cgd vs vds curve for a DMOS in switcher simulations&nbsp;



--- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:>> > > --- In LTspice@..., "Abhinav Joshi" <absjoshi@> wrote:> >> > From: "Helmut" helmutsennewald@...: Wed, 07 Aug 2013 00:05:48 To: LTspice@: [LTspice] How to plot cgd vs vds curve for a DMOS in switcher simulations&nbsp; > > > > > > &gt; > --- In LTspice@..., "absjoshi" absjoshi@ wrote:>> Hi,> > I am looking for a way to plot the cgd vs vds curve for a VDMOS device in a switcher simulations > > Kindly suggest.> > > Regards> AbhinavHello Abhinav,Isn't a gate charge curve the most interesting property?Best regards,Helmut> >> > Hello Helmut,> > It will be interesting to simulate the gate charge curve > > of DMOS. Would you suggest a way to do it in LT?> > &nbsp;> > Thanks.&gt; > Regards> > Abhinav> > > Hello Abhinav,> > I have uploaded an example.> > Files > Temp > AO4468_test.zip > > > Best regards,> Helmut>A second example with VDMOS.Files > Temp > RJK0330PDB_GateCharge.zip

--- In LTspice@..., jude thad <jukwai3@...> wrote:

Hello All,

I am kind of new to LTspice.
Please I want to know how to create entirely new component symbol in LTspice.
Thanks in advance for your help.

?
?Kind Regards,
Jude Anizoba

Hello Jude,

You could look this video.
LTspice IV: Adding Third-Party Models


There are also many links to tutorials.


Best regards,
Helmut

Hello All,

I am kind of new to LTspice.
Please I want to know how to create entirely new component symbol in LTspice.
Thanks in advance for your help.

?
?Kind Regards,
Jude Anizoba


[Non-text portions of this message have been removed]

Works!!, Thanks!!

--- In LTspice@..., "the_sky_falcon" <the_sky_falcon@...> wrote:

Hi,

I need to simulate a dynamic tunning circuit. I am thinking of using a triac (preferably optically isolated triac). I could not find any good instructions on the web for simulating triacs in LTSPICE. Could someone please explain/direct me to the instructions on how to use the triac in LTSPICE.

Your help is much appriciated.

Thank you,

Sky_Falcon

Hello Sky_Falcon,

Please open this HTML file all_files.htm and search with the
word triac or scr. I am sure you will find examples.

Files > Tables of Contents > all_files.htm



Best regards,
Helmut

Hi Helmut
Thank you very much for the solution and advice re. de-bugging lower level schematics.
Hi Andy
Thanks for your response. I honestly don't know enough about the inner workings of spice programs to know whether its important or not. I'll keep reading the Emails and someday I might learn enough.
Rgds
Mike

Hi,

I need to simulate a dynamic tunning circuit. I am thinking of using a triac (preferably optically isolated triac). I could not find any good instructions on the web for simulating triacs in LTSPICE. Could someone please explain/direct me to the instructions on how to use the triac in LTSPICE.

Your help is much appriciated.

Thank you,

Sky_Falcon

I need the model of filament lamp and xenon lamp, thanks!

A Xenon (arc) lamp is VERY different, as I'm sure you probably know.
I don't think we have one in this group's Files area.

Andy

But IIRC someone has modelled a spark gap surge protector which might be modifiable to represent a xenon lamp, if someone new the appropriate parameters.
--
Scanned by iCritical.

Hi.
I put in the TEMP folder example. File: BETA=F(BF).Zip .
I hope this helps.

Bordodynov.

In message
<CALBs-Tig6zF4aHJokFpN5ZvAVLR1eoCgqku8NA9TUS1FpTm3zw@...>,
dated Wed, 7 Aug 2013, Andy <Andrew.Ingraham@...> writes:

English is probably not his native language. The question might have
been translated to English by computer.

It could be, as shown by the untranslated words asimula??o and dimuir
(that may include a typo). The original is Portuguese.
--
OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk
Why is the stapler always empty just when you want it?

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

I have a circuit that have transistors, and I need to know what is the effect on the output current of my circuit when the beta of the transistor increase from 300 to 400 and also decrease from 300 to 100. Any idea how to simulate this on LTspice? Thanks.

Hello Heinz-W,



Thanks to Philippe's suggestion, I find some lamp models in our file section.

Yes you are correct, I need to build some detailed lamp models, using different drive voltages and with virous power.?
First, I need to get some standard structure of ?lamp model, and second, ?I am trying to understand how to adopt the detailed parameters, when changed voltage and power.
Thank you for your help!

Qilin

________________________________
From: Heinz-W. Schockenbaum <schockenbaum@...>
To: LTspice@...
Sent: Thursday, August 8, 2013 3:54 AM
Subject: [LTspice] Re: lamp model in Ltspice or Pspice




--- In LTspice@..., Garin Zhang <garin_zhang@...> wrote:

Hi,

I want to some simulation in ltspice, and a set of lamp models are needed.?

At least two models I remember in our file section. See Basier philippe contribution.

Problems to adapt details? Tell us voltge and current of your lamp.
And type.. LED, filament, fluorescent, neon lamp ...

hws



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[Non-text portions of this message have been removed]