LTSpice is a version of SPICE from Linear Technology

learn more… | top users | synonyms

0
votes
0answers
14 views

Convergence problem in pspice but not in ltspice

I am trying to simulate a circuit in LTSPICE and it simulates without any convergence problems. However when I copy the netlist into pspice and try it simulate it I get strange results. It keeps ...
1
vote
1answer
27 views

LTspice: Vary a capacitor's value over time

I want to vary a capacitor's value over time. A previous question (LTspice: Vary a resistor's value over time) asked how to vary a resistor's value over time. One of the answers was to use a ...
0
votes
0answers
21 views

modeling AC resistance proximity and skin effect using LTSPICE

I'm designing an air-core loop receiving antenna from <1Hz - 50kHz. Is there a way to approximately model the skin/proximity effect using lumped circuit parameters in SPICE software? I think you ...
0
votes
2answers
43 views

When I run the schemetic in LTSPICE,waves don't change direction.Why aren't waves changing direction here?

What pulse should I set to produce a waveform like in the graph?
0
votes
1answer
36 views

Why isn't current through D2 0 in LTSPICE? [on hold]

The current through d2 should b zero as it is reverse biased. Why dosen't ltspice software show zero current? - If I am doing somethin wrong then kindly make correction and tell me what to do to ...
0
votes
1answer
52 views

AC/DC wall adaptor as LTSpice Analog behavior model (ABM)

Suppose a circuit shuld be supplied ( in real life ) from a wall mount AC/DC adaptor. The adaptor has a nominal voltage of 12VDC 500mA. With no load the adapter puts out 21.6V. After some measurement ...
0
votes
0answers
33 views

Help Converting a PSPICE MOSFET .LIB to an LTSPICE .SUB

I am designing a buck-boost regulator for a course at school and I would like to use the OnSemi ntk3139p PMOS transistor. OnSemi provides a few spice models for this part and I am getting stuck ...
0
votes
0answers
25 views

LTSpice parameter sweep of multiple values

I have designed a boost converter for my power electronics class in LTSpice. The thing works just fine, now all I have to do it fiddle with the component values and frequency to describe the trends I ...
0
votes
0answers
17 views

Simulation of ic1 Bel 1895 in LT spice

I am doing an electronics project on condenser mic audio amplifier. And for this I want to first simulate the circuit in lt spice.But I am not getting how to simulate ic1 bel 1895 on lt spice? Can ...
0
votes
0answers
34 views

Power feeder current and LTSpice simulation

I'm trying to develop a power feeder as already state in question Power feeder scheme adaptation. I have done some adjustments, now my circuit is The voltage regulator is an LM317. Since I have to ...
1
vote
1answer
51 views

LTspice MOSFET width sweep

I am trying to simulate the transfer characteristics of a CMOS inverter using LTspice. I want to sweep the MOSFET width and length and observe the effects on rise and fall times of the CMOS inverter. ...
0
votes
1answer
64 views

Where to get PSPICE models of ceramic resonators?

I wish to design and simulate IF filters using ceramic resonators and crystal oscillators in OrCAD Capture or LT SPICE. The default libraries don't have any ceramics, so anyone know where to download ...
0
votes
1answer
44 views

How to run new .meas commands without having to rerun the whole ltspice simulation?

I am trying to analyze a circuits properties over a certain range of component values, e.g. a PWM circuit for various settings of the control pot. For this I create a bunch of ...
0
votes
1answer
43 views

DC Motor inertia voltage drop

following a tutorial on the web I created in LTSpice a DC motor model, but I have a question about the results, the model is: and this is the spice netlist: ...
2
votes
0answers
79 views

LTSpice showing negative transistor power

I'm using LTSpice to model a LC oscillator, driven by a NPN transistor. When I used the power calculating function on the transistor, LTSpice indicated that during part of the cycle the power ...
0
votes
1answer
94 views

Calculation in LTspice “never” finishes

I'm currently using LTspice, and I have a problem with it "never" finishing calculating a certain circuit. When I say "never", I mean that it's still calculating an hour after it stated, even though ...
0
votes
1answer
175 views

How to calculate a circuits efficiency with the help of LTspice

Note that this is not a question for circuit critique (and lots of things could be said about this circuit) but this circuit is only the base for the discussion of further points. Here it is (an ...
1
vote
0answers
108 views

LTSpice missing an SSR Component?

I want to simulate some circuits with SSR component but LTSpice does not provide this. From Eagle and KiCad I learned I can create my own component diagram. I'm not sure if I can do this also with a ...
1
vote
2answers
206 views

IR2110 LTspice simulation weird behaviour

I am obtaining weird voltage behaviour at the gate of my high side mosfet controlled by IR2110 which is controlled by PWM. PWM configuration: Vinitial = 0 Von = 5v Tdelay = 0 Trise = 7u Tfall = 7u ...
-1
votes
1answer
104 views

How to plot the frequency response of transconductance of BJT with LTSpice

I need to plot the frequency response of the transconductance of this circuit in the picture with LTSpice but I don't know how. Can you please help me urgently how should I do it? Thanks
1
vote
1answer
53 views

How to plot sliding average in ltspice?

I would like to plot a sliding average of some voltages and currents. Ideally I would just add a new trace with some expression, but all expressions that I found so far only operate on single values. ...
-1
votes
2answers
102 views

Problem simulating a fixed transconductor with LTSpice

I am simulating a fixed transconductor circuit with LTSpice. When I apply \$1\$V for input voltage, (for DC Sweep) the voltage of collector of \$Q_1\$ has good amplitude (\$30\$mV to \$330\$mV) while ...
0
votes
1answer
77 views

Add permanent component in LTSpice from asc and asy

I'm trying to add a new permanent component (ULN2803) to LTSpice, having asc and asy files. I have read some tutorials in the web but focused on .lib and .sub files. How can I add the component from ...
1
vote
2answers
147 views

How reliable or trustworthy are LTSPICE demo circuits?

I'm looking at a few switching power supplies and one of the demo .asc files for the particular controller I was looking at really seems to fit my requirements. Can I use their schematics in designs ...
1
vote
1answer
509 views

Parts tolerance simulations in ltspice

I just recently found this tutorial (and various other places mentioning a similar technique) when trying to evaluate how one of my circuits behaves when using real world components with real world ...
0
votes
0answers
66 views

Inverse Nyquist Plot (damping factor) in LTSpice possible?

Looking forward to plot inverse Nyquist A11 (damping factor). So the inverse of the transfer function. Is it possible with LTSpice? Ps: Transfer 1/A11 Nyquists are no problem.
0
votes
0answers
27 views

How is Waveform Compression used in LTSpice to determine Timestep?

The LTspice wiki says (and I believe this is basically copy pasted from the offical documentation): Syntax: ...
3
votes
1answer
117 views

LTspice: Noise simulation AND AC analysis in one plot

Is it possible to run a noise simulation and an AC simulation independently from one another and display the results in the same plot? Or better, is there a way to determine the SNR in one single ...
0
votes
0answers
56 views

asymmetric supply voltage for an OP AMP

I'm trying to amplify a signal with the bandwith of 500Hz - 10Khz, to do that I'm the circuit in LTspice using an asymmetric supply for the OP : the resistance R5 is just to keep things ...
0
votes
3answers
105 views

Stepped Sine Wave in Spice

I'm interested in simulating a circuit using a stepped sine wave input. I want to sample a sine wave at regular intervals and have the output constant during each interval, making an output that looks ...
4
votes
2answers
167 views

Are the stock transistor models in LTspice accurate at RF?

Just checking, I'm doing some experimenting of small signal RF design in LTspice.
0
votes
2answers
81 views

Creating an adjustable output regulator, in LTspice

Firstly, I'm having some trouble with simulating a variable resistor in LTspice.. I am wondering if this can be done? Also, does anyone have any advice on how to theoretically analyse this circuit? I ...
1
vote
1answer
259 views

How to use .step param with more than two parameters in LTSpiceIV

I need to do three transient simulations with different values of certain resistors (conveniently called R1 and R2) in each. What I mean to do exactly is this: Sim. 1: R1 = 1 k\$\Omega\$, R2 = 10 ...
1
vote
2answers
114 views

Designing a Filter

I am trying to design a filter which has the following Bode plot, So according to this site I designed the filter as shown below, As the two cross over frequencies are f1 = 50 Hz and f2 = 200 ...
2
votes
1answer
144 views

How to design a SPICE model from data sheet?

I am new to SPICE simulation and I am looking for spice model file of LTC 1065 data sheet can be found here here. I searched a lot on Google but I could not find ...
2
votes
1answer
496 views

Is there a spice directive to export waveform data in LTspice?

http://www.linear.com/solutions/1815 The above web-page explains how to export the waveform data to a text file. You basically run the LTspice simulation, clicking on the waveform window, go to ...
0
votes
0answers
23 views

How do I specify a parameter for a specific component in LTSpice?

I have a schematic which uses two center-tapped transformers. I found that I can specify the ratio between the two sides of the transformer by adding the directive ".param ratioT=0.3". Now that I ...
1
vote
1answer
799 views

Importing 3rd Party Models into LTSpice

I'm new to LTSpice but have the basics figured out (laying out a schematic, setting up simulation, running) and have done so with the basic but very well stocked library included. Of course my issue ...
0
votes
1answer
159 views

Cross-conducting half-bridge

I attached an LTspice schematic, a very simplified version of a MOSFET half-bridge driven by a push-pull isolated signal transformer. The FETs are cross-conducting, but their gate pulses are not ...
1
vote
2answers
168 views

Viewing netlist on native ltspice for mac

I have a mac os x 10.9.3 and I run the native ltspice on it. I cannot seem to access the netlist (the text file version of the schematic) on it. Looking at the website: ...
5
votes
2answers
290 views

Automate LT-SPICE?

I'm running a lot of simulations in LT-Spice, and I need someway to run them all either sequentially or at the same time. I was going to use Python, but I'm not entirely clear on how I would get ...
0
votes
1answer
96 views

Current sink - work in simulator, doesn't work in real

I've built current sink to drive wheatstone bridge. I've counted that I must reach current ~0.2mA to properly working whole measure system. Picture below present my current sink (I use MCP6001 op ...
0
votes
1answer
113 views

LTspice earthing information

In my simulation I require Earth on my chassis so that filter could be simulated. But I am not getting how to make an Earth in LTspice. Please note: This question is regarding ' LTspice ' ...
0
votes
0answers
146 views

Iron Core in LTSpice

I'm currently assembling a circuit in LTSpice which makes use of iron core transformers and inductors. There's only 1 type of inductor in LTSpice, which is also used to make the transformer. I would ...
0
votes
1answer
222 views

How to comment at the end of a command in LTspice?

Commenting in a spice file is quite straightforward. Start a line with an * and the entire line is a comment. The first line is ...
3
votes
2answers
301 views

How to suppress current spikes in transistor feedback loop

I am trying to pulse a load with a small constant current pulse (2mA @ 500us). The load does unfortunately have an unknown capacitance in the range 10nF - 1uF, parallel with an unknown resistance ...
1
vote
1answer
199 views

How to create Spice / LTSpice repeatable damped sinusoid

Is there a more elegant and/or simpler method to model a repeating, damped sinusoid from SPICE or LTSpice rather than chaining the damped SINE sources in series? Below is a schematic and the ...
1
vote
1answer
109 views

Where is the text for the symbol stored in LTspice?

The following is an image of the symbol opamp.asy. I opened the same file using Notepad++ and have pasted the contents below: ...
0
votes
1answer
668 views

LTspice: How to convert .asc file to netlist?

Using LTspice I can create .asc files which contain the information about my circuit. Is there a way to convert this information to a netlist? I am looking for a ...
1
vote
3answers
2k views

Is there a portable alternative to LTspice? [closed]

I am constantly on the move and come across many computers to which I have access and which have some version of Windows installed. I was wondering if there's a portable alternative to LTspice (or if ...