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Re: Including model with process corners for mosfets

 

--- In LTspice@..., "Tony Casey" <tony@...> wrote:

<snip>
--- In LTspice@..., "RobertTalty" <rtalty@> wrote:


Hi Tal,
If you right click on the device, you should get the
"component attribute editor" window
the Prefix will be MN, change this to XN.
The Value NMOS needs to be changed to match the subcircuit name.

That's about all you will need to do.

regards
Robert
</snip>
Hello Robert,

I think you mean ctrl-right-click. For the NMOS symbol, you don't get the component attribute editor unless you do this, you get the "choose new MOSFET" dialogue. For the NMOS4 device, right-clicking brings up the monolithic device editor instead.

Regards,
Tony
Thanks Tony,
my bad! you do need to use CNTL-right click to get the required menu
-robert
Re: Caps smaller than 0.5 uF?

John Woodgate
 

In message <j4pek9+j80b@...>, dated Wed, 14 Sep 2011, sepulchre10 <sepulchre10@...> writes:

When I look in the list the smallest shown is 0.5uF. When putting together a schematic with smaller caps, eg. 470pF I don't know any of the info on them other than the value. I see that the ones in the list have all the needed data. Is there a database or other info on smaller caps?
There are just too many different parts. If you want to simulate using specific catalogued parts, you have to build your own library, using the characteristics from the data sheets of the parts you want to use.

However, for very many purposes, you can simulate using the default parts, not adding any more characteristics, with little risk of serious error.
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
When I point to a star, please look at the star, not my finger. The star will
be more interesting.
Re: Caps smaller than 0.5 uF?

Tony Casey
 

--- In LTspice@..., "sepulchre10" <sepulchre10@...> wrote:

When I look in the list the smallest shown is 0.5uF. When putting together a schematic with smaller caps, eg. 470pF I don't know any of the info on them other than the value. I see that the ones in the list have all the needed data. Is there a database or other info on smaller caps?

Thanks,
Ken
Hello Ken,

That's probably for two reasons: because LTspice was/is primarily intended to evaluate switchmode power supply chips, capacitors appropriate to that application are supplied. The other reason, I suspect, is that for lower value capacitors, i.e. small ceramics, their parasitics are often not significant for typical applications - I'm thinking particularly of tuned circuits that are dominated by the inductors' Q.

However, for some other applications too, it is vital that the capacitor parasitics are explicitly entered. You will have to find the data yourself, and enter it for each capacitor. To assist me, I have an ESR and ESL calculator that I wrote in Excel that uses equations derived from a best fit to published data from Kemet and Murata to estimate these values on a component by component basis. It's not perfect, but it's close enough for starters.

Unfortunately, sometimes there is just no substitute for some getting your hands dirty and doing the grunt work yourself.

Incidentally, I believe it is more efficient to use the parasitics included in LTspice inductors and capacitors than to have explicit discrete parasitic components, even though you lose the convenience of being able to see them at a glance on a schematic. Does keep it neater and less cluttered though, although some folk don't seem to be too bothered by schematics that look like they were drawn by a drunken spider. But that's getting off-topic. :-)

Regards,
Tony
Re: Caps smaller than 0.5 uF?

 

If you need the extra info, then you probably already have a capacitor
picked out. So use its datasheet to fill in the blanks. Otherwise just edit
the value.

-- Nick

On Tue, Sep 13, 2011 at 11:38 PM, sepulchre10 <sepulchre10@...> wrote:

**


When I look in the list the smallest shown is 0.5uF. When putting together
a schematic with smaller caps, eg. 470pF I don't know any of the info on
them other than the value. I see that the ones in the list have all the
needed data. Is there a database or other info on smaller caps?

Thanks,
Ken



[Non-text portions of this message have been removed]
Re: Including model with process corners for mosfets

Tony Casey
 

<snip>
--- In LTspice@..., "RobertTalty" <rtalty@...> wrote:


Hi Tal,
If you right click on the device, you should get the
"component attribute editor" window
the Prefix will be MN, change this to XN.
The Value NMOS needs to be changed to match the subcircuit name.

That's about all you will need to do.

regards
Robert
</snip>
Hello Robert,

I think you mean ctrl-right-click. For the NMOS symbol, you don't get the component attribute editor unless you do this, you get the "choose new MOSFET" dialogue. For the NMOS4 device, right-clicking brings up the monolithic device editor instead.

Regards,
Tony
Re: Simple model for diffin-diffout amp

 

Hi AG,
I would caution against using a simple E source based fully differential amp model. Usually G source with appropriate resistor results in a much better behaved model.

I believe I suggested you download some ADC models. within that ADC collection are some fully differential CMOS opamp / OTA models.

For a very simple model I would use

.subckt ideal_differential_op_amp Vinm Vinp Outp VCM Outm
R1 Outp N001 1
R2 N001 Outm 1
G1 N001 Outp Vinp Vinm 100MEG
G2 Outm N001 Vinp Vinm 100MEG
G3 0 N001 VCM N001 100MEG
.ends ideal_differential_op_amp

you can also include output caps to limit the bandwidth and change the resistor values to model the output impedance.

I cant give you the exact models I use at work because they don't really belong to me.

regards
Robert

--- In LTspice@..., "Apparajan" <dg1@...> wrote:


I am re-posting this since I din't get a boo or an aye or nay..
Cheers
AG
--- In LTspice@..., "Apparajan" <dg1@> wrote:

I have uploaded my model
Temp-->File-->>E_model_for_diffamp.asc
It is a very simple model that models the differential and common mode loop gains. I have other more complicated models that model slew-rate, bandwidth, etc. However my most complicated model seems to be much simpler than what is commercially available? They also have a disclimer that they don't model offset, psrr, cmrr etc.? What gives...
Caps smaller than 0.5 uF?

 

When I look in the list the smallest shown is 0.5uF. When putting together a schematic with smaller caps, eg. 470pF I don't know any of the info on them other than the value. I see that the ones in the list have all the needed data. Is there a database or other info on smaller caps?

Thanks,
Ken
Re: Including model with process corners for mosfets

 

Hi Tal,
If you right click on the device, you should get the
"component attribute editor" window
the Prefix will be MN, change this to XN.
The Value NMOS needs to be changed to match the subcircuit name.

That's about all you will need to do.

regards
Robert

--- In LTspice@..., "TALTITO" <sloimi@...> wrote:

Hi Robert,

I didn't understand your explanation.
When i use regular models, i just include a NMOS4 (PMOS4) device, change the model name to the one i want to use, and add a path to the model definition in the schematic, and that's it.

In this case the library is a subcircuit, and it doesn't work to me thee same way.


I uploaded what i doing to:


What am doing wrong?



--- In LTspice@..., "RobertTalty" <rtalty@> wrote:

Tal,
I don't understand.

This is a model file for a HVPMOS and HVNMOS.
you just add $ terminal NMOS4 or PMOS4 devices, with the appropriate model names to the schematic. Then add the correct .lib spice directive to the schematic. if everything matches than the model should extract properly and simulate correctly.

since it is a subcircuit you will probably need to change the device designator to X rather than M. thats about all.

-Robert



--- In LTspice@..., "TALTITO" <sloimi@> wrote:

Hi Helmut/Robert/Others

I think i succeded to do that with replacing ? oparator by the if() operator.
Now I noticed that the model library is in the form of a subcircuit.
Is it possible to include the subcircuit in a schematic?
(maybe using a general symbol or something??)
I am a little confused on how to include it in the schematics since I don't have a .asc file.

Thanks,
Tal
Re: Simple model for diffin-diffout amp

Apparajan
 

I am re-posting this since I din't get a boo or an aye or nay..
Cheers
AG

--- In LTspice@..., "Apparajan" <dg1@...> wrote:

I have uploaded my model
Temp-->File-->>E_model_for_diffamp.asc
It is a very simple model that models the differential and common mode loop gains. I have other more complicated models that model slew-rate, bandwidth, etc. However my most complicated model seems to be much simpler than what is commercially available? They also have a disclimer that they don't model offset, psrr, cmrr etc.? What gives...
Re: AC response

Ganesan
 

I am re posting this since I didn't get aye or nay...
Cheers
AG

On 9/10/2011 6:46 PM, Ganesan wrote:


I can run different ac simulations with different frequency resolutions
and range..
Is there a way to merge the plot files.?
Cheers
A. Ganesan

===================================================================================

On 9/10/2011 6:41 PM, Ganesan wrote:

The list seems to work..But the interpolated output on the plot looks
funky... I can live with it..
Cheers
A. Ganesan

On 9/10/2011 6:16 PM, Helmut wrote:



--- In LTspice@... <mailto:LTspice%40yahoogroups.com>
<mailto:LTspice%40yahoogroups.com>
<mailto:LTspice%40yahoogroups.com>,
Ganesan <dg1@...> wrote:

I forgot to add, I don't know how to do variable resolution for
transient analysis either...
Cheers
A. Ganesan

On 9/10/2011 4:43 PM, Apparajan wrote:

I have a filter with some sharp notches and flat pass-bands. I
want to
be able to simulate it with variable resolution.
For example
.ac lin 10 20 50 lin 1000 50 70 oct 20 70 3k lin 1000 3k 3.8k
(linearly sweep the frequency 10 points from 20 to 50 hz;
high resolution of 1000 points between 50 to 70 HZ ( power supply
rejection notch;
Flat region from 70 to 3 khz and
a high resolution sweep of 1000points between 3k and 3.8k
(transition
band)
How do I do this in LTspice...?
Cheers
A. Ganesan
Hello,

There is only the option of lin, dec, oct and list in the
.AC-command. This means you would have to use "list", but it
would be a big effort to create the 10000 or more frequency
values.
The AC-simulation runs so fast, that you can simulate the
whole span with high resolution, even if you end with 100000
or more frequency-points.

I also don't know of any simple solution for .TRAN.
A possible workaround may be a dummy-source creating bursts.
This may force the automatic timestep calculator in LTspice
to reduce the time step.

Best regards,
Helmut
Re: CD4060 and CA3130 spice models request

 

Hi KMR,

I think the nearest you are going to get to a CD4060 LTspice model is by using a CD4020 which is similar to the CD4060 but the CD4020 has not got an attendant oscillator. You can remedy this descrepancy in features between the two devices by adding an RC/Xtal oscillator using an external to the chip nand gates RC/Xtal oscillator to drive the CLK input of the CD4020 and 'Hey presto ! ' you have got a very similar to the CD4060 working set up. The CD4020 has an LTspice model and symbol in our LTspice library.

Let me know how you get on.

Good luck and regards,

Michael




To: LTspice@...
From: kmr4uall@...
Date: Tue, 13 Sep 2011 19:07:26 +0000
Subject: [LTspice] CD4060 and CA3130 spice models request






hi
i am a new member
please help me i wants pspice models for these ic's

IC = CD4060 (CMOS 14-STAGE RIPPLE-CARRY BINARY COUNTER/DIVIDER AND OSCLLLATOR )
and CA3130 (15MHz, BiMOS Operational Amplifier with MOSFET Input/CMOS Output )

please help me






[Non-text portions of this message have been removed]
Re: CD4060 and CA3130 spice models request

Ganesan
 

Maybe substituting with A models and Helmut's expertise will get him
over the hump..
It did for me.. Thanks everybody..
Cheers
AG

On 9/13/2011 4:22 PM, Rick wrote:



--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
Ganesan <dg1@...> wrote:


Ganesan,

PSPICE logic devices or primatives won't wotk with LTspice.

RICK
Re: CD4060 and CA3130 spice models request

 

--- In LTspice@..., Ganesan <dg1@...> wrote:


Ganesan,

PSPICE logic devices or primatives won't wotk with LTspice.

RICK
Re: CD4060 and CA3130 spice models request

Ganesan
 



*

31 Oct 2006, 1:39 AM
doom49


Joined on 10-14-2006
Posts 4
A model for CD4060 CMOS 14 Stage Ripple-Carry Binary Counter/Divide
I am not successful to find a model for this I.C., do someone of you
knows where I can find it?




Thanks, Roby.



07 Nov 2006, 2:30 AM
peleus


Joined on 10-31-2006
Posts 2
Re: A model for CD4060 CMOS 14 Stage Ripple-Carry Binary Counter/Divide
Hi Roby.
In case you haven't found the model you need it is not very difficult to
make the one. All you need is a schematic of the CD4060 logic which is
easy to search for and then create the model utilizing LOGICEXP, PINDLY
and CONSTRAINT digital behavioral primitives available in pspice for
modeling digital devices. If you take a look at some digital library in
pspice you'll see that some models are built using the latter primitives.
Good look. D.

***

On 9/13/2011 3:56 PM, Tony Casey wrote:



--- In LTspice@... <mailto:LTspice%40yahoogroups.com>,
"KMR" <kmr4uall@...> wrote:

hi
i am a new member
please help me i wants pspice models for these ic's

IC = CD4060 (CMOS 14-STAGE RIPPLE-CARRY BINARY COUNTER/DIVIDER AND
OSCLLLATOR )
and CA3130 (15MHz, BiMOS Operational Amplifier with MOSFET
Input/CMOS Output )

please help me
Perhaps you should try a Pspice forum? This is a group for LTspice.

I feel sure that if you looked in the Files section of the group site,
you would probably find information that might help you.

Almost certainly, any Pspice model you find for a CD4060 will not work
in LTspice, unless it is transistor level model.

Regards,
Tony

Regards,
Tony
Re: CD4060 and CA3130 spice models request

Tony Casey
 

--- In LTspice@..., "KMR" <kmr4uall@...> wrote:

hi
i am a new member
please help me i wants pspice models for these ic's

IC = CD4060 (CMOS 14-STAGE RIPPLE-CARRY BINARY COUNTER/DIVIDER AND OSCLLLATOR )
and CA3130 (15MHz, BiMOS Operational Amplifier with MOSFET Input/CMOS Output )

please help me
Perhaps you should try a Pspice forum? This is a group for LTspice.

I feel sure that if you looked in the Files section of the group site, you would probably find information that might help you.

Almost certainly, any Pspice model you find for a CD4060 will not work in LTspice, unless it is transistor level model.

Regards,
Tony

Regards,
Tony
Re: Starting LTspice GUI from script file loading .sch and .cir - Linux

Tony Casey
 

--- In LTspice@..., "Axel K" <axelmklein@...> wrote:

Hi *,

In Ubuntu with Wine I want to have a setup of 4 LTSpice GUIs started together. I'd like to have a schematic and a .cir file loaded for every instance of LTspice.

Does anybody know how to load two files, a .sch and a .cir, at the start from a script?
The line
<env WINEPREFIX="/home/xxxx/.wine" wine C:&#92;&#92;Program&#92; Files&#92;&#92;LTC&#92;&#92;LTspiceIV&#92;&#92;scad3.exe -wine AAAA.sch AAAA.cir &>
does not work.

Thank you in advance.

Axel
Hello Axel,

Running four instances of LTspice from a bash shell is not a problem, but I don't think it's possible to open two files at once, either in Windows or Linux, from the command line. I've tried in both and failed.

It probably depends on the computer (number of cores etc), but when running from a bash shell, I've had up to 20 instances of LTspice running netlists in batch mode before problems set in. This is from a Python script, in which I check how many processes are currently active.

What you want is not possible, as far as I can tell. SCAD3.exe only seems to accept only one target file as a command line argument, even in batch mode. Makes sense, really.

Regards,
Tony
Sensitivity Anlysis..

Apparajan
 

Let s take a simple 2 resistor divider and a battery I want to step one of the resistors by 1% or 10%.(small change sensitivity v. large change sensitivity ) I want to plot
"(Delta(Vout)/Vout)/(Delta(R)/R)"... How do I do this? Or has this question been already answered..?
Cheers
AG
Re: Pole/Zero analysis

 

Hello to all,

Please stop the discussion about Pole Zero Analysis.
It has been beaten to death. It's totally off topic now.

Best regards,
Helmut
Moderator
Starting LTspice GUI from script file loading .sch and .cir - Linux

 

Hi *,

In Ubuntu with Wine I want to have a setup of 4 LTSpice GUIs started together. I'd like to have a schematic and a .cir file loaded for every instance of LTspice.

Does anybody know how to load two files, a .sch and a .cir, at the start from a script?
The line
<env WINEPREFIX="/home/xxxx/.wine" wine C:&#92;&#92;Program&#92; Files&#92;&#92;LTC&#92;&#92;LTspiceIV&#92;&#92;scad3.exe -wine AAAA.sch AAAA.cir &>
does not work.

Thank you in advance.

Axel
Re: Pole/Zero analysis

Tony Casey
 

<snip>
There is a long story to this, featuring another of P Bax's invaluable
contributions, but it really is OT here.
--
</snip>
Yes, I knew that sooner or later you would send this discussion into a siding. :-)

Going back to Peter Baxandall: the man was a genius, and all done without Computer Aided Disease - er, I mean Design.

Tony
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