Strange LTspice Problem

Started by Jim Thompson in sci.electronics.basics4 years ago 8 replies

Strange LTspice Problem... Received LTspice schematic (.ASC) from customer), all .ASY symbols in the same directory. Open schematic with...

Strange LTspice Problem... Received LTspice schematic (.ASC) from customer), all .ASY symbols in the same directory. Open schematic with LTspice, can't see any of the symbols. Clue: Doesn't balk and say can't find symbol... Any ideas? (I can't get a post to take on the LTspice list, so I've sent an E-mail to Helmut, as well as this post.) ...


LTSpice and OpAmp Oscillation

Started by M. Hamed in sci.electronics.basics8 years ago 3 replies

I've built a discrete transistor OpAmp, and when the input was off, I saw it oscillating. So, I got interested in OpAmp oscillation...

I've built a discrete transistor OpAmp, and when the input was off, I saw it oscillating. So, I got interested in OpAmp oscillation and compensation. The main criterion is that a Phase shift of 180 degrees occur when the loop gain is higher than 1. I tried to demonstrate that in LTSpice but couldn't. I'm not sure if it's an LTSpice limitation, or something I'm doing. I opened up the incl...


LTspice Symbols

Started by Jim Thompson in sci.electronics.basics3 years ago 1 reply

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...


LTspice E-mail Address List Hacked?

Started by Jim Thompson in sci.electronics.basics5 years ago 2 replies

I don't know if the LTspice List has been hacked but I'm suddenly barraged with spam, like ~100 E-mails per day... sent to an address I use only...

I don't know if the LTspice List has been hacked but I'm suddenly barraged with spam, like ~100 E-mails per day... sent to an address I use only for LTspice. So I changed my address. (Easy for me, I maintain ~200 different E-mail addresses just to cope with such situations :-) (All junk sent from googlegroups... just what you'd expect :-) ...Ji...


74HC4046 Model Development

Started by Jim Thompson in sci.electronics.basics5 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...


LTspice questions

Started by Bill Bowden in sci.electronics.basics5 years ago 4 replies

Does LTspice assume some value of Q when simulating parallel LC circuits where the resistance of the inductor and ESR of the capacitor are not...

Does LTspice assume some value of Q when simulating parallel LC circuits where the resistance of the inductor and ESR of the capacitor are not specified? I notice I get different results where the L or C resistance is not stated, but the simulator works ok and just displays weird waveforms. It seems to assume something. Another question I have is how to write a directive to sweep a bandpa...


Resistance of switch component (SW) in LTspice?

Started by Bill Bowden in sci.electronics.basics6 years ago 3 replies

How do I define the resistance of the SW (switch) component in the LTspice library? Apparently it's 1 ohm, and I'm trying to simulate a MOSFET...

How do I define the resistance of the SW (switch) component in the LTspice library? Apparently it's 1 ohm, and I'm trying to simulate a MOSFET (IRF-640 or similar) of 180 milliohms. Thanks, -Bill


LTspice question

Started by Bill Bowden in sci.electronics.basics6 years ago 4 replies

How do I view a waveform relative to some point other than ground using LTspice? For example, how do I display the waveform of one side of a...

How do I view a waveform relative to some point other than ground using LTspice? For example, how do I display the waveform of one side of a LC circuit relative to the other when neither side is grounded? Thanks, -Bill


74HC4046 Model Development

Started by Jim Thompson in sci.electronics.basics5 years ago

I have posted a first-pass attempt at a 74HC4046 model at... http://www.analog-innovations.com/SED/HC4046_SUB.zip This is just the VCO...

I have posted a first-pass attempt at a 74HC4046 model at... http://www.analog-innovations.com/SED/HC4046_SUB.zip 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 LTspice, please send me any error messages, so I can refine my skills > :-}


LTSpice

Started by Michael Robinson in sci.electronics.basics7 years ago 3 replies

I need to simulate a circuit with an lm393 comparator in it. I went to the yahoo group and got a file called lm393_st.txt. I renamed it...

I need to simulate a circuit with an lm393 comparator in it. I went to the yahoo group and got a file called lm393_st.txt. I renamed it lm393.sub and put it in the sub folder. Then I drew my circuit using a universal op amp symbol, which I named lm393. LTSpice doesn't recognize it, with or without an include statement. What do I do? --------------------------------------- Poste...


LTspice Tip

Started by Jim Thompson in sci.electronics.basics2 years ago 10 replies

As I work my way to a Universal OpAmp Spice Model that you only have to feed the subcircuit 10-12 numbers from the datasheet, I observe that...

As I work my way to a Universal OpAmp Spice Model that you only have to feed the subcircuit 10-12 numbers from the datasheet, I observe that LTspice struggles with what I would consider ordinary hyperbolic functions (bounded, all derivatives exist, are finite, and continuous)... making a straight line out of a transfer curve with soft limiting on each end... and churning... churning... churni...


Stepping multiple parameters in a simulation

Started by Jim Thompson in sci.electronics.basics4 years ago

A question presented on the LTspice list by John Woodgate prompted my answer, which may be of interest to other...

A question presented on the LTspice list by John Woodgate prompted my answer, which may be of interest to other LTspice/PSpice/whatever users: Here's an extreme example of multi-parameter stepping... In this example "Case" was stepped 1, 2, 3, 4 to get all the combinations needed by the test (IBIS model generation :-


Interesting Spice Netlisting Quirk

Started by Jim Thompson in sci.electronics.basics4 years ago 1 reply

This time I'll try not to hit "Send" before I enter some content :-( In developing Spice models/subcircuits it's useful to include within the...

This time I'll try not to hit "Send" before I enter some content :-( In developing Spice models/subcircuits it's useful to include within the subcircuit declaration the models used. But if you add a line to your development schematic... .MODEL D D It doesn't appear in the netlist, it appears in the .CIR file (this applies to all Berkeley-adhering Spices, but not to LTspice... LTspice...


LTspice Seminar in Phoenix

Started by Jim Thompson in sci.electronics.basics3 years ago 15 replies

I don't know how many lurkers here are in the vicinity of Phoenix, but I will be attending the LTspice Seminar... Tuesday, November 4, 2014...

I don't know how many lurkers here are in the vicinity of Phoenix, but I will be attending the LTspice Seminar... Tuesday, November 4, 2014 8:00 a.m. - 2:00 p.m. Phoenix, AZ Doubletree by Hilton Hotel 2100 S. Priest Drive Tempe, AZ 85282 Tel: 1-480-967-1441) Perhaps some would like to join me after the seminar and tip a few ;-) Register here:


LTspice Tutorials now available

Started by Jim Thompson in sci.electronics.basics4 years ago 35 replies

LTspice Tutorials now available on the Simulation Tools & Macros page of my website... http://www.analog-innovations.com/ ...

LTspice Tutorials now available on the Simulation Tools & Macros page of my website... http://www.analog-innovations.com/ ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |...


HC4046_VCO Now available as LTspice SCHEMATIC (.ASC)

Started by Jim Thompson in sci.electronics.basics4 years ago 6 replies

Here is my first pass at the HC4046 (VCO portion only), now in LTspice format... ...Jim...

Here is my first pass at the HC4046 (VCO portion only), now in LTspice format... ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems |


Mixed mode simulation in FEMM/LTspice

Started by Nina Volodina in sci.electronics.basics4 weeks ago 1 reply

Please point me on some tutorial on using FEMM and LTspice in couple to do mixed-mode gauss simulation/optimization (magneto-mechanical @ FEMM +...

Please point me on some tutorial on using FEMM and LTspice in couple to do mixed-mode gauss simulation/optimization (magneto-mechanical @ FEMM + electrical processes @ SPICE with data interchange between sim ticks). PS: Does FEMM supports CUDA ?


Temperature compensation in LTSpice?

Started by Bill Bowden in sci.electronics.basics5 years ago 5 replies

Is it possible to simulate circuit performance using LTSpice under different temperature conditions? Say you have a single NPN transistor with...

Is it possible to simulate circuit performance using LTSpice under different temperature conditions? Say you have a single NPN transistor with grounded emitter and a collector load and a resistor from base to collector so the collector voltage is about half the supply voltage. I understand the result would depend on the HFE of the transistor, temperature, and maybe not very stable. Just wonde...


AN: TL598 Spice Model

Started by Jim Thompson in sci.electronics.basics2 years ago

Awhile back someone on the LTspice List requested a TL598 Spice model. While somewhat obsolete, it intrigued me, and proved to be somewhat...

Awhile back someone on the LTspice List requested a TL598 Spice model. While somewhat obsolete, it intrigued me, and proved to be somewhat of a !#$* to model... but it caused me to develop a few new functions in my behavioral modeling repertoire. It can be found at TL598.zip on the Device Models & Subcircuits Page of my website... including an LTspice symbol. Modeling is based only fro...


LTSpice question

Started by Bill Bowden in sci.electronics.basics3 years ago 5 replies

I've noticed some LTSpice simulations indicate a higher than expected transistor current gain (HFE). I drew up a simple emitter follower circuit...

I've noticed some LTSpice simulations indicate a higher than expected transistor current gain (HFE). I drew up a simple emitter follower circuit using a 2N3904 transistor and it indicates the emitter current at 1.6 amps (3 volts across 2 ohms in the emitter) and a base current at 24 milliamps for a HFE gain of 66. I didn't know a little 2N3904 transistor would operate at 1.6 amps and sti...