LTSpice simulator of my oscillator is far from reality; bad models?

Started by Clifford Heath in sci.electronics.design8 years ago 25 replies

Folk, Thanks to some good help here in the past, I have a nice clean oscillator (for my new fox transmitters), but I'm having trouble with...

Folk, Thanks to some good help here in the past, I have a nice clean oscillator (for my new fox transmitters), but I'm having trouble with the LTSpice simulation at higher frequencies. I'm assuming that the Intersil Spice model for the CA3046 is bad, and I know JT has a better one. Anyhow, I have two questions about the attached LTSpice schematic. 1) When I set it to 30MHz, LTSpice ...


Dumb LTSpice question - subckt model

Started by Anonymous in sci.electronics.design8 years ago 12 replies

I've never used a mfr model that was a subckt before; I've always added the .MODEL to the LTSpice library file, or edited an existing...

I've never used a mfr model that was a subckt before; I've always added the .MODEL to the LTSpice library file, or edited an existing device. This Vishay MOSFET has a more complex model though, and she ain't loadin' Jim. LTSpice says it can't find the model for M1. I even tried putting the definition right in the .asc, still no joy. I followed the LTSpice help info, as best I could. A...


LTspice XVII

Started by JM in sci.electronics.design6 years ago 8 replies

I just stumbled across LTspice XVII today - I never realised there had been any development post LTspice IV. Very glad to see some long...

I just stumbled across LTspice XVII today - I never realised there had been any development post LTspice IV. Very glad to see some long awaited improvements to the UI, especially the floating windows support. Give it a try!


LTspice, a great program, but that UI!

Started by rickman in sci.electronics.design6 years ago 133 replies

Every time I want to do something with LTspice I have to fight the UI something wicked. Doing anything relating to commands is pure...

Every time I want to do something with LTspice I have to fight the UI something wicked. Doing anything relating to commands is pure torture. I eventually figured out how to do what I wanted, but it is amazing how poor not only the UI is, but the documentation. I have learned programming languages by reading the manuals. But I can't decipher the .MEAS statement in LTspice along with m...


LTspice Loafing?

Started by rickman in sci.electronics.design5 years ago 64 replies

I was running some simulations on LTspice and it is not even using 5% of my CPU. Nothing else is topping it and the entire computer is pretty...

I was running some simulations on LTspice and it is not even using 5% of my CPU. Nothing else is topping it and the entire computer is pretty much at idle. What could be limiting the speed? One of the main reasons I bought a laptop with an i7 processor was to speed simulations. Is this wasted on LTspice or am I doing something wrong? -- Rick C


S-parameter curves in LTspice

Started by Jeroen Belleman in sci.electronics.design8 years ago 18 replies

Call me dense, but after many years of using LTspice, during which many times I inserted return-loss bridges into my circuits to measure S11,...

Call me dense, but after many years of using LTspice, during which many times I inserted return-loss bridges into my circuits to measure S11, someone pointed out to me that LTspice has a directive for that. Just insert ".net V1 v(out)" somewhere into the schematic, and an S11 trace will become available. I'm still missing some of the finer points however: The resulting S11 only makes se...


Yahoo LTspice Shutting Down

Started by Steve Wilson in sci.electronics.design3 years ago 5 replies

Yahoo is terminating service on Oct 21. The LTspice group is moving to https://groups.io/g/LTspice/topics The migration is in process. The...

Yahoo is terminating service on Oct 21. The LTspice group is moving to https://groups.io/g/LTspice/topics The migration is in process. The AllFiles folder may be missing some updates. Helmut tried to update the file but Yahoo refused to allow it. These problems and other glitches will probably be corrected soon. Many people are pleased with the move. Due to the many problems with Yaho...


ltspice -- body effect and other matters

Started by Michael Robinson in sci.electronics.design12 years ago 11 replies

I need to be able to model a mosfet with values of L, W, Vth, Kprime, lamba and gamma, and I'm trying to figure out how to do this with...

I need to be able to model a mosfet with values of L, W, Vth, Kprime, lamba and gamma, and I'm trying to figure out how to do this with LTSpice. Looking at ltspice mosfet models, they don't have a separate value for K. They have Cgs, W and L. K is a function of Cgs, W, L, and electron mobility. So I could sort of kluge my own mosfet model by choosing Cgs so that K comes out just right. ...


LTspice Symbols

Started by Jim Thompson in sci.electronics.design5 years ago 4 replies

Having attended an LTspice seminar yesterday in Arizona, and lunching with Mike Engelhardt (*), I learned a number of tricks... Main trick I...

Having attended an LTspice seminar yesterday in Arizona, and lunching with Mike Engelhardt (*), I learned a number of tricks... Main trick I learned is that it is trivial to make auto-generated symbols... so I will be gradually updating my Device Models & Subcircuits Page to include LTspice symbols (.asy) 8-) (Roughly 1/3 are done today... be aware that you will have to adjust model call...


How to use John Chan L in LtSpice?

Started by Maynard A. Philbrook Jr. in sci.electronics.design8 years ago 9 replies

How do I use John chan L model on the form in Ltspice? I can't seem to find a way to instruct LTspice to use it over the standard? ...

How do I use John chan L model on the form in Ltspice? I can't seem to find a way to instruct LTspice to use it over the standard? I looked for a model card to use but I don't see it what I was looking for? All it shows is how to do it in at the text file level, I want to do it on the form? Or do I need to write an include file for that specific L? If so, then I assume when ...


LTspice: X-Axis Variable

Started by Jim Thompson in sci.electronics.design2 years ago 10 replies

In LTspice, is there a way to change the X-Axis variable? In PSpice I can do a PWL simulation, then change the X-Axis variable (in Probe) to...

In LTspice, is there a way to change the X-Axis variable? In PSpice I can do a PWL simulation, then change the X-Axis variable (in Probe) to be a voltage within the circuit, thus displaying hysteresis. I can't find a similar function in LTspice. ...Jim Thompson -- | James E.Thompson | mens | | Analog In...


LTSpice

Started by OldGuy in sci.electronics.design9 years ago 26 replies

So does LTSpice or some other graphical spice support Triacs Unijunctions PUTs Diac SCR Where can I find simple models for these...

So does LTSpice or some other graphical spice support Triacs Unijunctions PUTs Diac SCR Where can I find simple models for these to use with LTSpice of some free graphical spice? Yes, I need unijuction and triac and etc support. --- news://freenews.netfront.net/ - complaints: news@netfront.net ---


Monospace font in LTspice XVII

Started by Simon S Aysdie in sci.electronics.design5 years ago

Courier New is gone? No Unicode? LTspice IV had Courier New. None of the new and limited set seems to be monospaced.

Courier New is gone? No Unicode? LTspice IV had Courier New. None of the new and limited set seems to be monospaced.


Is this Intel i7 machine good for LTSpice?

Started by Joerg in sci.electronics.design8 years ago 237 replies

Folks, Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated that the Intel i7 is a really good processor for LTSPice....

Folks, Need to spiff up my simulation speeds here. IIRC Mike Engelhardt stated that the Intel i7 is a really good processor for LTSPice. According to this it looks like the 4790 is the fastest of the bunch: http://www.intel.com/content/www/us/en/processors/core/core-i7-processor.html So, what do thee say, is the computer in the Costco link below a good deal for LTSpice purposes? htt...


LTSpice: Complex numbers?

Started by Joerg in sci.electronics.design9 years ago 6 replies

Folks, Is there a way to coax LTSpice to display complex numbers in the form of x+jY (or x-jy if leading phase)? -- Regards,...

Folks, Is there a way to coax LTSpice to display complex numbers in the form of x+jY (or x-jy if leading phase)? -- Regards, Joerg http://www.analogconsultants.com/


output file with ltspice

Started by Jean-Pierre Coulon in sci.electronics.design3 years ago 7 replies

How can I cause ltspice to make an output file (extension = .out) with the initial voltages, BJT info and outputs of my .print...

How can I cause ltspice to make an output file (extension = .out) with the initial voltages, BJT info and outputs of my .print commands? Bye, -- Jean-Pierre Coulon


Flip-Flop in LTSpice, set/reset assertion?

Started by Joerg in sci.electronics.design3 years ago 20 replies

Today I found that a simulation wasn't working right because the set and reset on the flip-flop (dflop) in LTSpice has the set and reset inputs...

Today I found that a simulation wasn't working right because the set and reset on the flip-flop (dflop) in LTSpice has the set and reset inputs active high. Yet every modern flip-flop is active low. So I had to invert everything on those inputs just for the simulation. The "Special Functions" instructions in LTSPice are silent about this issue. Does this date back to the days of Methusa...


how to flip a component in ltspice?

Started by Komal Swami in sci.electronics.design8 years ago 5 replies

there is a facility to rotate a nmos4 and pmos4 in ltspice but i want to flip my component. so please suggest me any solution.

there is a facility to rotate a nmos4 and pmos4 in ltspice but i want to flip my component. so please suggest me any solution.


EvoSpice 4.1 Free Optimizer for LTSpice IV

Started by Anonymous in sci.electronics.design10 years ago 1 reply

EvoSpice 4.1 is now available for free. http://evospice.site88.net/ It automatically adjusts component values in a LTSpice IV simulation to find...

EvoSpice 4.1 is now available for free. http://evospice.site88.net/ It automatically adjusts component values in a LTSpice IV simulation to find the optimum solution according to the objectives you have set.


74HC4046 Model Development

Started by Jim Thompson in sci.electronics.design10 years ago 23 replies

I have been notified by Helmut Sennewald that the LTspice encryption process hides the node sequence. So please...

I have been notified by Helmut Sennewald that the LTspice encryption process hides the node sequence. So please revisit... http://www.analog-innovations.com/SED/HC4046_SUB.zip for a corrected version. This is just the VCO portion for now, and just the variable part; suitable only for LTspice. Please try it out and let me know your comments, etc. Since I'm new to working with LTsp...