Author Topic: Imbecile (me) needs help with LTSpice  (Read 3152 times)

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Offline PeterFW

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Imbecile (me) needs help with LTSpice
« on: May 05, 2016, 08:10:44 pm »
Hello!
This is a bit over my head and i would be very appreciative if someone could help me.

There are a few circuits i would like to simulate, i can use LTSpice and it does what i want.
But... the components i would like to use (the LT original parts are too expensive) i can not simulate.
The parts i would like to have are a LMV324 and LMV339, the low voltage counterparts of the well known LM324 and LM339.

Although, for now, even a normal LM339 would make me fairly happy.
Can someone help me with that?
Yes, i tried Google, i tried to understand the whole deal but i am just too stupid at the moment to get this done...

Greetings,
Peter
 

Offline Zero999

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Re: Imbecile (me) needs help with LTSpice
« Reply #1 on: May 05, 2016, 08:16:42 pm »
SPICE models for those components can be found using a search engine.
 

Offline ZeTeX

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Re: Imbecile (me) needs help with LTSpice
« Reply #2 on: May 05, 2016, 08:23:41 pm »
Unfortunately, LTSPICE comes mostly with LT parts.
You can look on google for LM399 LTSPICE Model, and install them, doe most of the time you can get away by using replacement part, for example, you might get away with using LT1013 as LM358.
 

Offline edavid

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Re: Imbecile (me) needs help with LTSpice
« Reply #3 on: May 05, 2016, 08:24:30 pm »
It might be best to switch to TINA-TI, then you can use the models supplied by TI without any changes.
 

Offline rstofer

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Re: Imbecile (me) needs help with LTSpice
« Reply #4 on: May 05, 2016, 08:47:43 pm »
There's an LTSpice group on Yahoo and a separate LTSpice files group where they store the more permanent models.  Check the files section of both groups.

Google turned up an LM324 model:
http://ltwiki.org/?title=Components_Library_and_Circuits

It turned up an LM329:
http://ltwiki.org/?title=File:LM339.sub

The stuff is out there and it's all over the place.
 

Offline PeterFW

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Re: Imbecile (me) needs help with LTSpice
« Reply #5 on: May 05, 2016, 09:14:34 pm »
It might be best to switch to TINA-TI, then you can use the models supplied by TI without any changes.

That looks way better then LT Spice and i do love TI parts... thank you very much!

There's an LTSpice group on Yahoo and a separate LTSpice files group where they store the more permanent models.  Check the files section of both groups.

Thank you for the links, i got it working now!
The LM324 i allready had, that one will have to do instead of the LMV324.

Quote
The stuff is out there and it's all over the place.

I know, most people who ask these things are lazy bastards.
Let me assure you, i tried, i searched and not just for 5 minutes. I dit not come up with the links you posted.

Sometimes i wish there were a "I am not a lazy idiot, i really do need some help. I have searched and simply am stuck"-Button.

Greetings,
Peter
 

Offline f5r5e5d

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Re: Imbecile (me) needs help with LTSpice
« Reply #6 on: May 05, 2016, 10:49:09 pm »
I wouldn't switch 'Spice versions because of included models - you will quickly need to learn to add 3rd party models to any version of Spice you end up using

LTSpice is however not a "training wheels" Spice - it has its obscurities but also very few limits for a free Spice - many EE with budgets still use free LTSpice
 

Offline timb

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Re: Imbecile (me) needs help with LTSpice
« Reply #7 on: May 05, 2016, 11:55:28 pm »
I wouldn't switch 'Spice versions because of included models - you will quickly need to learn to add 3rd party models to any version of Spice you end up using

LTSpice is however not a "training wheels" Spice - it has its obscurities but also very few limits for a free Spice - many EE with budgets still use free LTSpice

Exactly. LTSpice is very, very powerful. LT actually has a guy that works on it full time. It's probably the best SPICE engine you can get for under $10,000.

Whereas TINA-TI is just a feature limited version of the commercial TINA software licensed by TI; mind you, it isn't bad software, but it's engine isn't anywhere near as good as LTSpice.

TINA has a better UI and it's easier to use, but do you care about that or accurate simulation results? The company behind TINA has put a lot of development time into stuff like 3D breadboard views, which converts your schematic into a solderless breadboard layout and shows it to you in 3D. (Yes, seriously.) Though, TINA does have a cloud based edition now, which aside from being a bit buggy works well. The nice thing about it is the simulation is done on their servers, which really speeds complex designs up!

Anyway, there are plenty of guides that show you how to import 3rd party models into LTSpice; LT even has videos on their site showing you how to do it. There's also the aforementioned archives with ready to go LTS models.

Stick with it, it's well worth it.

(Oh, the other huge advantage that LTSpice has for me is it's Mac OS X native! I heard that the programmer, Mike, actually develops on the OS X version and then back ports to Windows, so Mac users get the latest features first! You wouldn't know it by looking at the OS X version's UI though...)

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Offline ZeTeX

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Re: Imbecile (me) needs help with LTSpice
« Reply #8 on: May 06, 2016, 09:49:45 am »
I wouldn't switch 'Spice versions because of included models - you will quickly need to learn to add 3rd party models to any version of Spice you end up using

LTSpice is however not a "training wheels" Spice - it has its obscurities but also very few limits for a free Spice - many EE with budgets still use free LTSpice

Exactly. LTSpice is very, very powerful. LT actually has a guy that works on it full time. It's probably the best SPICE engine you can get for under $10,000.

Whereas TINA-TI is just a feature limited version of the commercial TINA software licensed by TI; mind you, it isn't bad software, but it's engine isn't anywhere near as good as LTSpice.

TINA has a better UI and it's easier to use, but do you care about that or accurate simulation results? The company behind TINA has put a lot of development time into stuff like 3D breadboard views, which converts your schematic into a solderless breadboard layout and shows it to you in 3D. (Yes, seriously.) Though, TINA does have a cloud based edition now, which aside from being a bit buggy works well. The nice thing about it is the simulation is done on their servers, which really speeds complex designs up!

Anyway, there are plenty of guides that show you how to import 3rd party models into LTSpice; LT even has videos on their site showing you how to do it. There's also the aforementioned archives with ready to go LTS models.

Stick with it, it's well worth it.

(Oh, the other huge advantage that LTSpice has for me is it's Mac OS X native! I heard that the programmer, Mike, actually develops on the OS X version and then back ports to Windows, so Mac users get the latest features first! You wouldn't know it by looking at the OS X version's UI though...)
What SPICE engines do you know that are better then LTspice and cost over 10,000$?
 

Offline matkar

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Re: Imbecile (me) needs help with LTSpice
« Reply #9 on: May 06, 2016, 07:47:13 pm »
Here is asy file for LMV321 which you should put (unzipped) in C:\Program Files\LTC\LTspiceIV\lib\sym\Opamps folder plus a SUBCKT model which you can append to your schematic as a spice directive:
Code: [Select]
*//////////////////////////////////////////////////////////////////////
* (C) National Semiconductor, Inc.
* Models developed and under copyright by:
* National Semiconductor, Inc. 
*
*/////////////////////////////////////////////////////////////////////
* Legal Notice: This material is intended for free software support.
* The file may be copied, and distributed; however, reselling the
*  material is illegal
*
*////////////////////////////////////////////////////////////////////
* For ordering or technical information on these models, contact:
* National Semiconductor's Customer Response Center
*                 7:00 A.M.--7:00 P.M.  U.S. Central Time
*                                (800) 272-9959
* For Applications support, contact the Internet address:
*  amps-apps@galaxy.nsc.com
*/////////////////////////////////////////
*LMV321  BICMOS  Low Voltage General Purpose Op Amp
* MODEL FORMAT: PSPICE
* Rev:  11/07/97 -- ABG
*/////////////////////////////////////////
* Connections       non-inverting input
*                   |  inverting input
*                   |  |  positive power supply
*                   |  |  |  negative power supply
*                   |  |  |  |  output
*                   |  |  |  |  |
.SUBCKT  lMV321     3   2   4   5   6
* Features:
* 2.7V and 5V Operation
* Low Supply Current:  130uA at VCC=5V
* Stable for AV = +1
*/////////////////////////////////////////
**************************************
EOX 120 10 31 32 2.0
RCX 120 121 1K
RDX 121 10 1K
RBX 120 122 1K
GOS 10 57 122 121 1.0
RVOS 31 32 1K
RINB 2 18 1000
RINA 3 19 1000
DIN1 5 18 DMOD2
DIN2 18 4 DMOD2
DIN3 5 19 DMOD2
DIN4 19 4 DMOD2
EXX 10 5 17 5 1.0
EEE 10 50 17 5 1.0
ECC 40 10 4 17 1.0
RAA 4 17 100MEG
RBB 17 5 100MEG
ISET 10 24 1e-3
DA1 24 23 DMOD1
RBAL 23 22 1000
ESUPP 22 21 4 5 1.0
VOFF 21 10 -1.25
DA2 24 25 DMOD1
VSENS1 25 26 DC 0
RSET 26 10 1K
CSET 26 10 1e-10
FSET 10 31 VSENS1 1.0
R001 34 10 1K
FTEMP 10 27 VSENS1 1.0
DTA 27 10 DMOD2
DTB 28 29 DMOD2
VTEMP 29 10 DC 0
ECMR 38 10 11 10 1.0
VCMX 38 39 DC 0
RCM2 41 10 1MEG
EPSR 42 10 4 10 1.0
CDC1 43 42 10U
VPSX 43 44 DC 0
RPSR2 45 10 1MEG
FCXX 57 10 VCXX 100
DCX1 98 97 DMOD1
DCX2 95 94 DMOD1
RCX1 99 98 100
RCX2 94 99 100
VCXX 99 96 DC 0
ECMX 96 10 11 10 1.0
DLIM1 52 57 DMOD1
DLIM2 57 51 DMOD1
ELIMP 51 10 26 10 99.3
GDM 10 57 3 2 1
C1 58 59 1e-10
DCLMP2 59 40 DMOD1
DCLMP1 50 59 DMOD1
RO2 59 10 1K
GO3 10 71 59 10 1
RO3 71 10 1
DDN1 73 74 DMOD1
DDN2 73 710 DMOD1
DDP1 75 72 DMOD1
DDP2 71 720 DMOD1
RDN2 710 71 100
RDP 720 72 100
VOOP 40 76 DC 0
VOON 77 50 DC 0
QNO 76 73 78 NPN1
QNP 77 72 79 PNP1
RNO 78 81 1
RPO 79 81 1
VOX 86 6 DC 0
RNT 76 81 100MEG
RPT 81 77 1MEG
FX 10 93 VOX 1.0
DFX1 93 91 DMOD1
VFX1 91 10 DC 0
DFX2 92 93 DMOD1
VFX2 10 92 DC 0
FPX 4 10 VFX1 1.0
FNX 10 5 VFX2 1.0
RAX 122 10 MRAX 1.014000e+03
* Input Offset Voltage
.MODEL MRAX RES (TC1=1e-05)
FIN1 18 5 VTEMP 0.833333
FIN2 19 5 VTEMP 1.16667
* Input Bias Currents
CIN1 2 10 1e-12
CIN2 3 10 1e-12
* Common Mode Input Capacitance
RD1 18 11 5e+08
RD2 19 11 5e+08
* Diff. Input Resistance
RCM 11 10 9.75e+09
* Common Mode Input Resistance
FCMR 10 57 VCMX 562.341
* Low Freq. CMRR
FPSR 10 57 VPSX 2000
* Low Freq. PSRR
RSLOPE 4 5 1e+12
* Slope of Supp. Curr. vs. Supp. Volt.
GPWR 4 5 26 10 0.00013
* Quiescent Supply Current
ETEMP 27 28 32 33 0.286906
RIB 32 33 MRIB 1K
* Temp. Co. of Input Currents
.MODEL MRIB RES (TC1=0.00283713)
RISC 33 34 MRISC 1K
.MODEL MRISC RES (TC1=-0.003)
RCM1 39 41 17782.8
CCM 41 10 5.30516e-12
* CMRR vs. Freq.
RPSR1 44 45 10000
CPSR 45 10 5.30516e-11
* PSRR vs. Freq.
ELIMN 10 52 26 10 99.3
RDM 57 10 725.52
C2 57 10 1.09683e-10
ECMP 40 97 26 10 0.8
ECMN 95 50 26 10 0.2
G2 58 10 57 10 1e-06
R2 58 10 1378.32
GO2 59 10 58 10 100
* Avol and Slew-Rate Settings
EPOS 40 74 26 10 0
ENEG 75 50 26 10 0.01
* Output Voltage Swing Settings
GSOURCE 74 73 33 34 0.0006
GSINK 72 75 33 34 0.0016
* Output Current Settings
ROO 81 86 8.5
.MODEL DMOD1 D
.MODEL DMOD2 D  (IS=1e-17)
.MODEL NPN1 NPN (BF=100 IS=1e-15)
.MODEL PNP1 PNP (BF=100 IS=1e-15)
.ENDS lmv321

After restarting LT Spice just click Component icon and search for LMV321 in the specified folder.
Sorry, I don't have LMV339 model.
 

Offline AndyC_772

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Re: Imbecile (me) needs help with LTSpice
« Reply #10 on: May 06, 2016, 08:24:28 pm »
ST has an excellent library of op-amps for Spice, which is compatible with LTSpice.

http://www.st.com/st-web-ui/static/active/cn/resource/technical/ecad_models_and_symbols/cad_symbol_library/Opamps_ST.txt

Their server is down at the moment, but Google has the file cached.

It includes a symbol LMV3x, which I believe is the model for LMV324. You just need to have a read through the LTSpice documentation to learn how to incorporate it into a schematic... not hard once you've done it once.

Offline PeterFW

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Re: Imbecile (me) needs help with LTSpice
« Reply #11 on: May 09, 2016, 09:29:41 pm »
Hello and thank you everyone for the replys!

I got it working now and slowly am geting more comfortable with this program.
The main thing that i liked about the TI program was the (for me) vastly better user interface.
I will stick with LTSpice, slowly it gety less and less of a pain in the neck to use :)

Greetings,
Peter
 


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