Imbecile (me) needs help with LTSpice - Page 1
Forum section: electronics / beginners

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 05, 2016, 08:10:44 pm
content: 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

author: Zero999
author_rank: Super Contributor
timestamp: May 05, 2016, 08:16:42 pm
content: SPICE models for those components can be found using a search engine.

author: ZeTeX
author_rank: Frequent Contributor
timestamp: May 05, 2016, 08:23:41 pm
content: 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.

author: edavid
author_rank: Super Contributor
timestamp: May 05, 2016, 08:24:30 pm
content: It might be best to switch to TINA-TI, then you can use the models supplied by TI without any changes.

author: rstofer
author_rank: Super Contributor
timestamp: May 05, 2016, 08:47:43 pm
content: 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_CircuitsIt turned up an LM329:http://ltwiki.org/?title=File:LM339.subThe stuff is out there and it's all over the place.

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 05, 2016, 09:14:34 pm
content: Quote from: edavid on May 05, 2016, 08:24:30 pmThat looks way better then LT Spice and i do love TI parts... thank you very much!Quote from: rstofer on May 05, 2016, 08:47:43 pmThank you for the links, i got it working now!The LM324 i allready had, that one will have to do instead of the LMV324.QuoteI 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

author: f5r5e5d
author_rank: Frequent Contributor
timestamp: May 05, 2016, 10:49:09 pm
content: 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 usingLTSpice 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

author: timb
author_rank: Super Contributor
timestamp: May 05, 2016, 11:55:28 pm
content: Quote from: f5r5e5d on May 05, 2016, 10:49:09 pmExactly. 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...)

author: ZeTeX
author_rank: Frequent Contributor
timestamp: May 06, 2016, 09:49:45 am
content: Quote from: timb on May 05, 2016, 11:55:28 pmWhat SPICE engines do you know that are better then LTspice and cost over 10,000$?

author: matkar
author_rank: Regular Contributor
timestamp: May 06, 2016, 07:47:13 pm
content: 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:*//////////////////////////////////////////////////////////////////////* (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 2.0RCX 120 121 1KRDX 121 10 1KRBX 120 122 1KGOS 10 57 122 121 1.0RVOS 31 32 1KRINB 2 18 1000RINA 3 19 1000DIN1 5 18 DMOD2DIN2 18 4 DMOD2DIN3 5 19 DMOD2DIN4 19 4 DMOD2EXX 10 5 17 5 1.0EEE 10 50 17 5 1.0ECC 40 10 4 17 1.0RAA 4 17 100MEGRBB 17 5 100MEGISET 10 24 1e-3DA1 24 23 DMOD1RBAL 23 22 1000ESUPP 22 21 4 5 1.0VOFF 21 10 -1.25DA2 24 25 DMOD1VSENS1 25 26 DC 0RSET 26 10 1KCSET 26 10 1e-10FSET 10 31 VSENS1 1.0R001 34 10 1KFTEMP 10 27 VSENS1 1.0DTA 27 10 DMOD2DTB 28 29 DMOD2VTEMP 29 10 DC 0ECMR 38 10 11 10 1.0VCMX 38 39 DC 0RCM2 41 10 1MEGEPSR 42 10 4 10 1.0CDC1 43 42 10UVPSX 43 44 DC 0RPSR2 45 10 1MEGFCXX 57 10 VCXX 100DCX1 98 97 DMOD1DCX2 95 94 DMOD1RCX1 99 98 100RCX2 94 99 100VCXX 99 96 DC 0ECMX 96 10 11 10 1.0DLIM1 52 57 DMOD1DLIM2 57 51 DMOD1ELIMP 51 10 26 10 99.3GDM 10 57 3 2 1C1 58 59 1e-10DCLMP2 59 40 DMOD1DCLMP1 50 59 DMOD1RO2 59 10 1KGO3 10 71 59 10 1RO3 71 10 1DDN1 73 74 DMOD1DDN2 73 710 DMOD1DDP1 75 72 DMOD1DDP2 71 720 DMOD1RDN2 710 71 100RDP 720 72 100VOOP 40 76 DC 0VOON 77 50 DC 0QNO 76 73 78 NPN1QNP 77 72 79 PNP1RNO 78 81 1RPO 79 81 1VOX 86 6 DC 0RNT 76 81 100MEGRPT 81 77 1MEGFX 10 93 VOX 1.0DFX1 93 91 DMOD1VFX1 91 10 DC 0DFX2 92 93 DMOD1VFX2 10 92 DC 0FPX 4 10 VFX1 1.0FNX 10 5 VFX2 1.0RAX 122 10 MRAX 1.014000e+03* Input Offset Voltage.MODEL MRAX RES (TC1=1e-05)FIN1 18 5 VTEMP 0.833333FIN2 19 5 VTEMP 1.16667* Input Bias CurrentsCIN1 2 10 1e-12CIN2 3 10 1e-12* Common Mode Input CapacitanceRD1 18 11 5e+08RD2 19 11 5e+08* Diff. Input ResistanceRCM 11 10 9.75e+09* Common Mode Input ResistanceFCMR 10 57 VCMX 562.341* Low Freq. CMRRFPSR 10 57 VPSX 2000* Low Freq. PSRRRSLOPE 4 5 1e+12* Slope of Supp. Curr. vs. Supp. Volt.GPWR 4 5 26 10 0.00013* Quiescent Supply CurrentETEMP 27 28 32 33 0.286906RIB 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 17782.8CCM 41 10 5.30516e-12* CMRR vs. Freq.RPSR1 44 45 10000CPSR 45 10 5.30516e-11* PSRR vs. Freq.ELIMN 10 52 26 10 99.3RDM 57 10 725.52C2 57 10 1.09683e-10ECMP 40 97 26 10 0.8ECMN 95 50 26 10 0.2G2 58 10 57 10 1e-06R2 58 10 1378.32GO2 59 10 58 10 100* Avol and Slew-Rate SettingsEPOS 40 74 26 10 0ENEG 75 50 26 10 0.01* Output Voltage Swing SettingsGSOURCE 74 73 33 34 0.0006GSINK 72 75 33 34 0.0016* Output Current SettingsROO 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 lmv321After restarting LT Spice just click Component icon and search for LMV321 in the specified folder.Sorry, I don't have LMV339 model.

author: AndyC_772
author_rank: Super Contributor
timestamp: May 06, 2016, 08:24:28 pm
content: 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.txtTheir 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.

author: PeterFW
author_rank: Frequent Contributor
timestamp: May 09, 2016, 09:29:41 pm
content: 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 useGreetings,Peter