ltspice

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    LT spice OPAMP simulations

    Hi, For a school project I had to design a opamp for audio amplification. I now would like to do an ac analysis on just the intermediate stage to see the gain and input impedance yet i am not sure how to simulate this. I remeber a TA talking about adding a feedback resistor that is 0.1 AC 1T...
  2. E

    Issues Simulating Duffing Oscillator In LTSpice

    Hello. I am new to LT spice and I am having a lot of trouble simulating a duffing oscillator. I‘ve tried changing integration methods, changing tolerances, using .startup, using .uic, and lots of other things. I get two different errors depending on my settings (see image): 1) time step too...
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    2SA1708 and 2SC4488 NPN Transistors for SPICE

    Hi there! I am currently looking for 2SA1708 and 2SC4488 transistor models to integrate into Spice, but I could not find any model on the web. Could you please help me if you have the related models? Or can you please give me feedback about what parameters are the most important ones to model...
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    Questions about junction temperature

    hello, I have question about junction temperature. I thermal simulated the chip (CPM2-1700-0045B, CREE) in LTspice. However, I do not understand because it is very different from the chip (C3M0045065D, CREE) result. The result of the chip (C3M0045065D) is that the heat gradually increases and...
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    LM358 Subckt for LTspice

    Hi, I'm new at this forum and to LTspice. I need to know how to build either a new model or a sub-circuit for the LM358 device. Once I have the file LTspice manual tells me how to include it into the simulation. Thanks in advance for any input on this question.
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    Value to simulate igbt and diode in ltspice from datasheet

    I have igbt and diode data sheet used for inverter and rectifier circuit design. i need simulate inverter in ltspice using the voltage controlled switch component. How obtain to these values from the igbt/diode data sheet datasheet is attached here Name Description Units Ron Resistance in...
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    dc motor in ltspice/multisim

    hello. this (see first photo) is an h-bridge project on proteus. will be simulating it as well on ltspice/multisim but i cant seem to find the dc motor component. is this (2nd photo) the alternative dc motor model for it? kindly dont mind the values. im still learning the software so any...
  8. K

    need help with a ltspice circuit

    I need to create a circuit that monitors +12V . The circuit compares a +12V and a reference voltage of 5V. The circuit should then send a ground (0V) to a 20V buzzer (I have not put it in the circuit yet) causing the buzzer to sound when the 12V is removed. Knowing this Im trying to make a...
  9. R

    LT spice problems

    I would like to fully charge then discharge the capacitor using the two switches . Charge for 50s then discharge for another 50s seconds. Please help me. I am not getting the capacitor to discharge pass half the source voltage.
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    LTSPice filter

    Hello everybody, I am trying to simulate a line filter (Wurth Electronik) on LTSpice but I do not have the same result which is written in the datasheet for 50 ohm / 50 ohm sym. I joined my circuit, the datasheet and the .zip (including .lib and .asy) of the filter. Thank you for your time.
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    How to improve LTSpice

    Simple Question: How can LTSpice be improved? What are its good points? What are its bad points? What features are missing? If you had to rewrite the package from the start, what would you do differently? Would you like it to have more "Windows Like" features (CTRL-C, CTRL-V to copy and paste...
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    LTspice invert signal in AC analysis

    Hi Guys, Does anyone know if it's possible to create a circuit for an AC analysis that will invert another signal? I've tried all sorts of things (e.g. using behavioral elements), and looked on online, but have not been able to find a solution. The BV element can invert and multiply signals...
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    LTSpice Simulation Question

    Hello All, Currently I've been doing some parametric sweeps with components and temperature. If I perform both a parametric sweep with a temperature sweep is there a way to extract or plot the data for one of the temperature points? For example lets say I perform a transient sweep while...
  14. THD vs frequency

    Hi all I've found this link: https://www.audio-perfection.com/audio/audio-total-harmonic-distortion-analyzer-for-ltspice-making-thd-vs-amplitude-and-frequency-sweeps-in-ltspice.html I'm trying to understand how to use this script properly. Can someone tell me how I can plot the THD vs freq...
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    Help with smart twilight switch design LTSPICE

    The main specification consists in the resolution of a technical problem by the use of electronic systems It is proposed to design an Adaptive flashlight so that the light intensity depends on the brightness environmental. When there is a lot of ambient light the flashlight is off and according...
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    LTSPICE opamp circuit sim

    I'm trying to sim the input circuit of an audio EQ, but I'm getting only DC at the output. This is what I'm trying to simulate: It's the input section of this schematic: Here's what I've created, the .ASC is attached: I'm using an LT1057 model as it is described as a drop-in...
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    Problem with generation of triangular wave

    Hi! I am working with comparator (In LTspice). I have to compare a sine wave and a triangular wave. The triangular wave should be at 2kHz frequency. So this should be the configuration for triangular wave: However, the results show that it is not a 2kHz frequency:- Last time I checked...
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    Can't successfully add IRL1404Z to LTSpice

    Here is what I have tried: downloaded the simulation file from international rectifier irl1404z.spi (it is a .subckt file, not a .model file) moved it to the same folder as my project inserted an nmos device, M1 into the circuit Named the device type IRL1404Z added .inc IRL1404Z.spi (the...
  19. O

    LTSpice Half bridge inverter

    I am trying to create a simple half bridge inverter in LTSpice. I have chosen to use a purely inductive load and I am having some problems with the circuit. I am using a gate driver the IR2110a to drive the MOSFETS. The problems I am having are the output voltage (Vs-Va) is not as expected. I...
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    Synchronous Buck Converter with Negative Feedback Loop

    Hello, I am in the midst of creating a synchronous buck converter. The requirements of the converter is the following: Vin = 30V - 50V Vout= 3V - 5.5V Io >=12 A Now the power stage works perfectly with ideal as well as realistic components. After investigating that the power stage works, I...
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    Enable Pin vs Shutdown Pin

    Hello Everyone, I have a problem here... I am designing a board that I need a low voltage cutoff for... I want to use the Enable pin to do this... I have the circuit designed for a shutdown pin, but this is the opposite of the enable pin, right??? Here is my design in LTSpice... So here are...
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    LTspice Monte Carlo analysis vs. .meas command

    Hello. I designed some analog second-order all-pass filter in LTspice and provided Monte Carlo analysis as well. I want to evaluate the obtained AC results with .meas command, particularly: 1. Magnitude variation at pole frequency (.meas AC 'label' FIND mag(V(out)) AT 'freq value of interest')...
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    IF statement on LTspice

    Hi, I would like to create a variable resistor as following: R2=1 if i(R2)<1 R2=2 if 1<i(R2)<10 R2=3 if i(R2)>10 I know that the sintax is: R=if(condition,valueiftrue,valueiffalse) What about if I have three intervals? The .asc file and the IF statement law is also shown in the attached...
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    Problem with LTspice: Time stop too small

    Hi, I'm trying to create a variable resistor dependign from the value of current. Please find attached the .asc file. It doesn't work, when I run the simulation the following messages is presented: Analysis: Time step too small; initial timepoint: trouble with node "n002". Do you know how...
  25. D

    Problem with Electric and LTSpice

    I am completely new to this and am confused about a lot of things the way my professor wants us to set-up the stuff. Anyways, following the steps to the best of my ability, I ended up at this point here: A SCHEMATIC OF AN INVERTER. I did a DRC run and there were no errors with my schematic. The...
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