LTSpice Doesn't Allow Access To Parameters

[BrownOut]

Ok, now need to set the temperature coefficient of a resistor in a simulation, but when I bring up the parameter list, the TC isn't listed. I was digging around to see how others are simulating resistors with resistance dependent on temperature, and found This page. It's a very clever idea to use a current controlled voltage source (CCVS) to model the resistor. But, isn't this a little over complicated for a simple TC drift simulation? Should I just create a new resistor symbol and pass the TC or define a default? Has anyone tried this? Thanks.

 

[MikeMl]

Here is something that may help you

 

[BrownOut]

That's great, but I can't edit the netlist, and Help doesn't tell me how I can specify TC on the schematic. When I bring up a resistor's properties, I only get "value" "tolerance" and "Power Rating" TempCo isn't listed as a property I can edit.

 

[ericgibbs]

That's great, but I can't edit the netlist, and Help doesn't tell me how I can specify TC on the schematic. When I bring up a resistor's properties, I only get "value" "tolerance" and "Power Rating" TempCo isn't listed as a property I can edit.

hi D,
Have you tried 'select the resistor as though you want to change its value, on the same line as the value add, tc=xxxx'

 

[BrownOut]

Well I'll be damn. Thanks Eric, you always come through for me

 

[EncinoMan]

I am experimenting (learning my way around by trial and error) with LTSPICE as well as TINA7 after giving up on Quocs. It's using the free versions (in my experience) that have limitations such as you describe. What I've found is that TinaTI (Tina7? from Tex. Inst.) has the fewest limitations on the free versions. There are scads of sites online if you simply Google Tina Circuit Simulator. I even found a source for a FREE download of the Tina7 version which isn't normally free. I managed to get the install files downloaded before I lost the URL but I'm still looking and will post here.

So, why not give Tina a whirl? It's at least as user friendly as LTSpice and I like the display better. So far I've found the library of available components to be unlimited.

A WORD OF CAUTION! Whenever I recommend something it usually turns to poopoo ( I'm still too new to say ****! lol) I'm so new I haven't given much thought to an avatar so I may just use a photo of Groucho, my role model. He won't care. He's not using it himself.

EncinoMan

 

[BrownOut]

If there were a mixed-mode simulator download that accepted Verilog/VHDL, and actually works, I would be very interested.

 

[EncinoMan]

Thanks for the reply to my post, BrownOut. I almost feel like somebody HA! By the way, if my profile had been edited and posted, you would have seen that MY location is Mobile, AL. Furthermore, I'm also a Huntspatch expatriot who attended Lee High School for a few years. Small world, huh? When we went to the Space Museum it was a small wooden building on the Arsenal and my girlfriend and I sometimes were the only visitors present. Many of the Germans, including Dr. Von Braun, would often be around to answer questions or chew the fat. Von Braun was a nice man.

To your reply let me first say that I'm just learning the ropes in the Circuit Sim arena so I'm no authority. With that disclaimer I will gladly share what I think I know. I went to my TinaTI help page and here is a copy and paste quote:

Create and save .VHD (VHDL source file) and .UCF (User Constraint File, specifying the pin assignment within the FPGA) files from a digital circuit.

"Note that in order to generate proper .UCF files, you should place FPGA pin components on the schematic (available at the Special component toolbar) specifying the FPGA connection with the switches, displays and other controls on the FPGA board. Check the files in TINA's
EXAMPLES/VHDL/FPGA folder as examples and use this command to generate the related .VHD and .UCF files. Once these files are created, you can compile them with the freely downloadable Webpack program at FPGA and CPLD Solutions from Xilinx, Inc. under Download. Finally, download the resulting .BIT files into the TINALab FPGA or other Xilinx chip. Download the .BIT file into the TINALab FPGA or use the T&M | Download to FPGA Card…command."

There is no mention of additional (or any) cost OR to upgrading to the "PayFor" version. I THINK this may be what you're looking for. Again, I don't have the specific website URL for MY download but there are MANY sources and seemingly endless variations. Just do a Google search for Tina circuit simulator and browse. Meanwhile, I'll keep looking through my download for other clues.

Incidentally, I've noticed a good many of the others in here live North of the MD Line so we need to stick together. If they ever find out about grits and crawfish we'll never get rid of 'em!

Bob Bagwell
Mobile, AL

 

[EncinoMan]

I didn't realize how lengthy my last post was until it was too late to fix it. Sorry, I'll avoid that error in the future. Instead I'll try to make new errors.

Bob

 

[EncinoMan]

MORE TINA7 (TINATI):

Here is the "About" page from my download (verbatim (to help you locate the version I have to evaluate for your needs. At this point I'm not qualified to recommend.)

TINA for Windows
The Complete Electronics Lab

- Version 7.0.80.96 SF-TI
- Build date: 2009 April 6, 11:48:24 AM
- Copyright 1993-2009 DesignSoft, Inc. TINA-TI Special Complimentary
Basic Edition Distrubuted by Texas Instruments
- Copyright 2007 by DesignSoft-Texas Instruments

Bob

(later) found this site which looks promising: **broken link removed**

 

[BrownOut]

Hi EncinoMan, Huntsville is a great little town. I moved here from the West Coast in 2001, and never looked back. I love long Summer days on the Tennesse River and riding my motorcycle through the Applilacians. I actually live on Monte Sano, and can see all across the valley on clear days. I can hardly imagine ever leaving.

I'm going to look into TINA a little more. From the description you posted, it appears to be a schematic entry tool that generates VHDL, sort of like some of the old Orcad tools I've used. That's a little backards to me. I want to be able to enter VHDL, and I'm not all that interested in synthesis tools, at least for mixed signal designs, since mixed signal SOC's are still few and far between. I basically just want to amuse myself by doing mixed signal simulations. But like I said, I'll check more into it. I might be wrong.