## erreur: Time step too small sur LTspice

Started by in sci.electronics.design7 years ago 3 replies

Bonjour, Je simule mon circuit sur le logiciel "LTspice" et il m'affiche cet erreur là "Time step too small; time=153.341,...

Bonjour, Je simule mon circuit sur le logiciel "LTspice" et il m'affiche cet erreur là "Time step too small; time=153.341, timestep=1.43134e-013: trouble with u16:np-instance q:u16:3" s'il vous plait est ce que quelqu'un peut m'aider à résoudre ce problème ? Merci Fivota

## Arbitrary delay in LTspice

Started by in sci.electronics.design8 years ago 7 replies

Awhile back we were trying to figure out how to make a voltage-variable delay line in LTspice. Turns out there is a way to use one signal to...

Awhile back we were trying to figure out how to make a voltage-variable delay line in LTspice. Turns out there is a way to use one signal to delay another: there's an undocumented function delay(x,y). Unlike the documented one, delay y can be a simulation variable, like so: Version 4 SHEET 1 880 680 WIRE -96 112 -112 112 WIRE 96 112 80 112 WIRE 112 112 96 112 WIRE 304 112 288 112 ...

## TUTORIAL - Example 1, Using Femm to Calculate Component Values of Simple Microstrip to use in LTspice/PSpice

Started by in sci.electronics.design8 years ago 31 replies

I offer to share with you a TUTORIAL but don't know how to get it into your hands. The TUTORIAL is about 15kB, zipped, and describes the...

I offer to share with you a TUTORIAL but don't know how to get it into your hands. The TUTORIAL is about 15kB, zipped, and describes the step-by-step process of using FREE femm 4.2 to analyze a simple PCB structure to calculate values to then use in circuit simulation, LTspice/PSpice. The sequence can be modified for use in analyzing really complex structures, structures where th...

## Antenna Simulation in LTspice

Started by in sci.electronics.design10 years ago 41 replies

I am working on a simulation for a loop antenna in LTspice and I can't figure out why the signal strength features are what they are. The...

I am working on a simulation for a loop antenna in LTspice and I can't figure out why the signal strength features are what they are. The model uses a pair of loosely coupled inductors to model the transmitter and antenna loop with a separate pair of tightly coupled inductors to model the coupling transformer. A cap on the primary circuit is the tuning cap and a cap on the secondary is...

## Why is there no dual gate fets in LTspice?

Started by in sci.electronics.design10 years ago 30 replies

There are many kinds of them for instance from NXP.

There are many kinds of them for instance from NXP.

## LTSPICE model for Ge transistors

Started by in sci.electronics.design3 years ago 7 replies

Looking for models of Ge transistors I only found some that behaved like Si ones having a Vbe of 0.7V. Anyone can tell to find good...

Looking for models of Ge transistors I only found some that behaved like Si ones having a Vbe of 0.7V. Anyone can tell to find good ones? petrus bitbyter

## LT spice _ LM7812

Started by in sci.electronics.design9 years ago 12 replies

What is the substitute for LM7812 in LTspice ? I can find any...

What is the substitute for LM7812 in LTspice ? I can find any...

## TI's Web Bench question

Started by in sci.electronics.design2 years ago 9 replies

I can't find a way to get TI's model into LTspice. So, I tried TI's online simulator. It does not give a reasonable output even using their...

I can't find a way to get TI's model into LTspice. So, I tried TI's online simulator. It does not give a reasonable output even using their default schematic. And, it is glacially slow -- they say it might take up to 15 minutes to complete an analysis. Has anyone else had this problem?

## Helmut Sennewald RIP

Started by in sci.electronics.design2 years ago 5 replies

Sebastian Wolf informed us in the German NG that Helmut passed away: https://groups.io/g/LTspice/topic/74768321#121677 I still cannot...

Sebastian Wolf informed us in the German NG that Helmut passed away: https://groups.io/g/LTspice/topic/74768321#121677 I still cannot believe it :-( -- Regards, Joerg http://www.analogconsultants.com/

## LM386 & Spice

Started by in sci.electronics.design6 years ago 38 replies

I need to sim an LM386 amp to see what decoupling caps are neded for stability on end of life batteries. Is there a Spice model for this anywhere?...

I need to sim an LM386 amp to see what decoupling caps are neded for stability on end of life batteries. Is there a Spice model for this anywhere? My LTSpice seems to lack any of the IC models I'm likely to use. NT

## Anyone Know....

Started by in sci.electronics.design11 years ago 2 replies

Anyone Know who this is.... gazeee20@hotmail.com A definite POS, flooding my LTspice E-mail Inbox. Now filtered out. But I'll pay \$10...

Anyone Know who this is.... gazeee20@hotmail.com A definite POS, flooding my LTspice E-mail Inbox. Now filtered out. But I'll pay \$10 to anyone who takes a dump on his front porch ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | |...

## LTSpice LED parameters

Started by in sci.electronics.design5 years ago 66 replies

Here is what I have: .model LXHL-BW02 D(Is=4.5e-20 Rs=.85 N=2.6 Cjo=1.18n Xti=200 Iave=400mA Vpk=5 mfg=Lumileds type=LED) How do I change...

Here is what I have: .model LXHL-BW02 D(Is=4.5e-20 Rs=.85 N=2.6 Cjo=1.18n Xti=200 Iave=400mA Vpk=5 mfg=Lumileds type=LED) How do I change the Vf at a specified current? I suspect that it is more involved than just changing Rs. Thanks, Guys.

## Unconnected part LTSpice seems to need (weird ...)

Started by in sci.electronics.design11 years ago 81 replies

Folks, This is close to voodoo but repeatable. Unfortunately I can't disclose the schematic since it is for a client. Just wondering , anyone...

Folks, This is close to voodoo but repeatable. Unfortunately I can't disclose the schematic since it is for a client. Just wondering , anyone had this before? At the far end of a TX line I used to have a diode connected across because a previous version of a chip would have such a substrat path. Nice waveforms, fast sims. Everything as expected and peachy. Now the new iteration of the c...

## LTSpice query

Started by in sci.electronics.design3 years ago 15 replies

Greetings, gentlemen, The image below is how I've been representing variable resistors in LTS for like ever. But this circuit fragment -...

Greetings, gentlemen, The image below is how I've been representing variable resistors in LTS for like ever. But this circuit fragment - because it contains a disproportionately large number of variable resistors compared to everything else- really forced me to face up to the issue that I'm doing something wrong here. There must surely be a more elegant way than making up v.res out of two ...

## LED forward voltage drop with temperature

Started by in sci.electronics.design3 years ago 70 replies

LTSpice says that the forward voltage drop of LEDs have a positive coefficient. That is contrary to my thinking and to my measurements. Am I...

LTSpice says that the forward voltage drop of LEDs have a positive coefficient. That is contrary to my thinking and to my measurements. Am I doing something wrong?

## Are TI Pspice models encripted?

Started by in sci.electronics.design7 years ago 67 replies

I was going to try to load the TI TPS54335 spice model into LTspice but it looks encrypted. Is TI encrypting its spice models...

I was going to try to load the TI TPS54335 spice model into LTspice but it looks encrypted. Is TI encrypting its spice models now? http://www.ti.com/product/tps54335 Thanks

## Spice modelling of back EMF

Started by in sci.electronics.design7 years ago 71 replies

Hi all, I've been unable to get sensible results from simulating the voltage spike inductors generate when their magnetic fields collapse....

Hi all, I've been unable to get sensible results from simulating the voltage spike inductors generate when their magnetic fields collapse. The only possibility I can think of for this failure is that the standard inductor models have insufficient parameters for this purpose and require an extended parameter set. Like many of y'all I use LTspice, btw. Any ideas?

## Surrendering to the 555 Timer Option

Started by in sci.electronics.design3 years ago 34 replies

I've looked at a number of different oscillators and either I can't bend them to my will because they are not very good oscillators or they aren't...

I've looked at a number of different oscillators and either I can't bend them to my will because they are not very good oscillators or they aren't really amenable to simulation in LTspice. I need to turn on a sounder for 1 second out of 4. A low going pulse is good as I'm using a driver FET even if it's not needed just to maximize the voltage range. The circuit needs to be ena

## BD131 Spice Model Wanted

Started by in sci.electronics.design7 years ago 15 replies

Hi all, It still amazes me after all the years LTspice has been around the standard parts library in it remains so tiny. I don't think this...

Hi all, It still amazes me after all the years LTspice has been around the standard parts library in it remains so tiny. I don't think this long- standing defect in otherwise very good program will ever be fixed. So like anyway, has anyone got a model for a BD131 NPN transistor they could post here? TIA folks. CD

## LT spice, how to add model lib

Started by in sci.electronics.design4 years ago 3 replies

Hi all, simple question how do I add a library to ltspice. Lib from...

Hi all, simple question how do I add a library to ltspice. Lib from here. https://www.classe.cornell.edu/~ib38/teaching/p360/lectures/wk12/l35/11.1/74hc.lib I've watched a few videos, but not working so well. George H.