LTSpice is a version of SPICE from Linear Technology

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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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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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130 views

Is there a portable alternative to LTspice? [on hold]

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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23 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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30 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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26 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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70 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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47 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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100 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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122 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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61 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 ...
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45 views

Bireciprocal lattice wave digital filter

I am trying to model a bireciprocal Cauer filter in LTspice but I don't get the expected results. More precisely, using \$\gamma = \frac{re(p_i)-1}{re(p_i)+1} \$ where \$re(p_i)\$ is the realpart of ...
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48 views

How to fit MAX941 macromodel to LTSpice “opamp2”?

I am new to adding models to LTSpice. I have successfully added OPA350 from TI, but with MAX941 from Maxim Integrated I get some errors due to the LTSpice "opamp2" model does not have the same amount ...
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43 views

Syntax error in LTspice

I researched online and came across a code given here for PWM source in LTSPICE. When I save this .asc and try to open the same, I get the following error: Aborting: Unknown schematic syntax: ...
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61 views

How to break components in SPICE?

I've been learning SPICE over the past few days, using the LTSPICE program. One thing that just escapes me, is how exactly do we know when a component's absolute maximum ratings have been exceeded? ...
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63 views

spice representation for mechanical problems

As a mechanical engineer, for my work, I need to compute some displacements which are represented as a summation of frequency dependent admittances on a structural system and I would like to use this ...
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92 views

Singular error when putting a current source in series with a capacitor (ngspice)

I am getting singular errors when I simulate a current source in series with a capacitor with the following .cir file: ...
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98 views

Digital simulation display

I am new in the field of electronic circuit simulation and the two articles i am reading from http://en.wikipedia.org/wiki/Electronic_circuit_simulation http://en.wikipedia.org/wiki/SPICE have ...
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39 views

Spice Simulation model for LTC201, 202, 202

I'm looking for a spice simulation model for the analog switches from LT LTC201-203. Have anyone an idea where I can find them, on the LT site I couldn't find them?
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Why does this parallel->series rewrite change my AC simulation results a little?

Here are two circuits I've simulated. Both have a current source of \$\sin(\omega t)\$ mA with \$\omega=1000\$. They should be equivalent but give different simulation results. Here are the ...
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154 views

LTSpice: Silicon diode substitution improves Schottky clamp simulation

I'm simulating this circuit in LTSpice: The input is a 1 Mhz square wave with 10 ns rise and fall times. Plotted are the input, output as well as transistor base voltage. Now here is what ...
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458 views

LTSpice, MAC97A8 TRIAC model, Vgs error

I'm having some difficulty getting LTSpice to like a TRIAC model. The specific error it throws is "Missing model definition for VGT-0.65". The trouble is that VGT is a subcircuit parameter, not a ...
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112 views

How to draw an impedance in LTSpice?

I can draw a resistance or conductance in LTSpice, but how can I draw an impedance component? I've seen them drawn as unfilled rectangles before. I've tried searching the component list for ...
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102 views

LTSpice simulation trouble

I'm simulating a passband amplifier (some 80 - 200 MHz) stage with two transistors. I'm using LTSpice. When I simulate the transfer function I get a maximum gain at a given frequency, let's say 100 ...
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83 views

Spice Convergence error (Won't simulate)

I'm a trying to simulate the following circuit and I cannot work out why it won't converge. It used to work, but when I added R10 in it stopped working. The error can be seen in the screenshot. ...
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105 views

LTspice: How to make a time-variant mutual inductance coefficient in transformer model

I would like to make a transformer model with a time-variant mutual inductance coefficient. Does it work at (K1 L1 L2 var)?
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158 views

Measured VS Ltspice Difference in P-Chan JFET Attenuator

The following circuit is a slow switching +-15V audio signal attenuator: Why are the measured voltages (shown in white boxes) so different from the SPICE values (shown in the graph)? Note that ...
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Spice code for uplim and dnlim?

Does anyone know where I can get sources for LTspice's uplim and dnlim? I'm trying to port a netlist from LTspice to ngspice. ...
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123 views

SPICE Model For Voltage Reference

Anyone aware where can I find SPICE models for MAX6126, MAX6250 etc? I searched a lot and could not find. If anyone knows, can you please share the link/file?
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221 views

Why is the output from this astable 555 the reverse of it's simulation?

The simulator in LTSpice looked OK ... so I moved to the breadboard with an LED (eventually replaced the LED with a buzzer) at pin 3. One more difference in the assembled circuit is the condenser at ...
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94 views

Choosing a ground for ltspice circuit

I am just getting into this software. I construct my circuit, and it tells me to choose a ground. I only have experience with "ideal" circuits and circuit elements, and have only seen "ground" in the ...
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766 views

LTSpice Solar / photovoltaic simulation

I've been trying to simulate a solar cell with LTSpice to generate an I-V curve. The model I've been using is the simplified equivalent circuit model with a current source in parallel with a diode. ...
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305 views

how to vary the threshold voltage of a MOSFET for simulation in LTSPICE

I have a MOSFET circuit with multi-threshold voltages. I am using TSMC MOSFET with 180nm technology. How to specify these voltages in LTSPICE for simulation. Please help.
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324 views

Does LTSpice support a “Remainder” or “Modulus” function?

I am trying to change a parameter in LT Spice with if statements and make it change on whether a different value is even or odd. Mathematically, this would be easy with a remainder or modulous ...
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LTSpice simulation of rectifier slows down after short time

I have the following simple circuit set up in LTspice: Blue is on the output of the transformer and green from the rectifier. If I don't include a capacitor this works fine and the simulation goes ...
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How do you simulate voltage noise with LTSpice?

Is there a way to setup a voltage supply with voltage jitter/noise? I want to experiment with filtering out noise on various voltages etc. but not sure how to configure LTSpice to create a noisy ...
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1answer
288 views

Can I simulate any component with LTSpice?

I'm trying to build a very basic 3.3V supply, but would like to simulate the circuit in LTSPice if possible, before I physically build the circuit. I'm using a couple of components not found in ...
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431 views

How can one label a node with more than one name in SPICE/ LTspice

Update: node name "alias" (aka synonym) resolution seems to work fine in simple circuits... even though one of the two names "goes away" it's doing what I'd expect by namely referring everything to ...
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Simulating real world transformer with LTSpice

I'm studying LTSpice, and I'm playing in transformer simulation. I want to modelize a real world power line transformer in a reasonable way: I mean I don't need an exact simulation of some specific ...
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602 views

Unijunction transistor in LTspice?

I would like to simulate a simple oscillating circuit involving an unijunction transistor. I do not find such component in LTspice so I figure I need to import one. Could please show me step by step ...
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137 views

IIR frequency transformations

(this might be a tad long) I am trying to make frequency transformations for an IIR in LTspice, from low-pass to band-pass, following these steps: continuous time low-pass H(s) > H(z) > frequency ...
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528 views

Voltage regulators in SPICE software

I am having trouble figuring out how to add voltage regulators to my circuit for SPICE simulation. The regulator is a 78L10AC voltage regulator, 10V, 5% output tolerance, LP package. I have most of my ...
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444 views

Spice model, can't figure it out

I am using LTSpice with the following NMOS model from the library included in the famous book 'Sedra & Smith, Microelectronic circuits' : ...
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Why is my simple boost converter giving me such a high peak output voltage?

I am trying to understand switch-mode power supply fundamentals through a simulation in LTSpice. I wanted to build an excruciatingly simple boost converter circuit following a teaching model often ...
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199 views

Symmetrical components [SOLVED]

I am trying to build an abc to positive/negative/zero components transformation block (in LTspice), I did it, but sometimes I get erroneous behaviour: DC levels seem to be "omitted" at the output for ...
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818 views

Interpretation of input impedance graph of a filter

I tried to simulate the input impudance of a multipass feedback low pass filter. I want to know if the graph I got is right, and if so, what does it show? Also, what is that dashed line about? And ...
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DC power supply simulation trouble

I'm trying to simulate a relatively simple AC->DC power supply in LTSpice, but it's not quite cooperating with me. I've followed this schematic: only replacing potentiometers with resistors due to ...
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509 views

Simulating Multiple Feedback Low Pass filter using LTSPICE

I am trying to simulate the follwoing circuit in LTSpice IV. What I am looking for is overall performance in frequency domain. I downloaded and readed a lot of LTSpice guides, but none of them were ...
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LTSpice Automation

I have a battery-powered boost converter and I'm attempting to measure the maximum input (battery) voltage droop under various load conditions of high current draws (different ...
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Why does LTSpice say that my “Matrix is singular” for this ideal-transformer circuit?

I'm trying to do find the voltage over R1 in the following circuit, where L1/L2 is an ideal transformer. LTSpice complains that the "Matrix is singular". Why? I've tried to play around with lots of ...