LTSpice is a version of SPICE from Linear Technology

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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 ...
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23 views

LTSpice load simulation [on hold]

I have to check using LTSpice if my power feeder is able to provide an amount of current. How can I simulate a load in order to check this? thanks
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30 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. ...
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37 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 ...
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35 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 ...
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33 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: ...
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74 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 ...
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1answer
79 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 ...
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103 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 ...
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94 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 ...
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2answers
153 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 ...
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80 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
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44 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. ...
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92 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 ...
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61 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 ...
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2answers
130 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 ...
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340 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 ...
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55 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.
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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: ...
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107 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 ...
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50 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 ...
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3answers
87 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 ...
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159 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.
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75 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 ...
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162 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 ...
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109 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 ...
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136 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 ...
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407 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 ...
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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 ...
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677 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 ...
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143 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 ...
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137 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: ...
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256 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 ...
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93 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 ...
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103 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 ' ...
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125 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 ...
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179 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 ...
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276 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 ...
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173 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 ...
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105 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: ...
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567 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 ...
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3answers
1k 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 ...
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117 views

A good reference for modeling pmos transistors in LTspice?

I've been trying to learn how to use LTspice, and I'm attempting to create a model for a pFET I've been using/will use on a real board. However, since my specific transistor isn't already in ...
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100 views

Modeling transformer in Ltspice

I am trying to model a transformer of 1:100 ration in Ltspice, here is the picture of it The above circuit is stepping up the input voltage by 100 times but I see something strange which is when I ...
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312 views

LTSpice - Printing resultant parameters based on expressions

I'm designing a circuit but I'm computing the values of components based on a set of design values. For example, ...
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3answers
130 views

Voltage dip on MOSFET switchable current shunt

I have the following circuit built up in LTSpice which will be used to switch in different sense resistors for current measurements. The mAEn signal switches the M1 transistor on at t=10ms which ...
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332 views

How to model IR LED Diode in SPICE [duplicate]

How does one model an IR diode in SPICE? Specifically, the TIL38. Datasheet here: http://www.supermoduul.com/PDF/TIL38.pdf I get it that Is needs to be found - ...
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2k views

Simulating SMPS with ideal switch in LTSpice?

Yes, this in a portion of a homework assignment (hence the idealized and slightly asinine problem statement). Aside from solving the circuit (which I have done), I am supposed to simulate the ...
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4answers
260 views

Waveform generation with opamp

I need to design a circuit that generates the voltage waveform shown in the Figure 1 when an input voltage is applied as shown in Figure 2. Figure 1 and Figure 2 are in the second link below. Only ...
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225 views

Pseudo-Nmos inverter in LTSPICE

In LTSPICE, I've built a pseudo-NMOS inverter and I've got 2 tasks to do using it. 1) I've a initial guess for Wn value of NMOS. I start the simulation with this value however, I need to optimize it ...