Questions tagged [ltspice]
Anything related to LTspice. LTspice is a SPICE simulation, schematic capture, and waveform viewer program from Linear Technology. LTspice is freeware with a very liberal license, it is lightweight, and isn't crippled in any way.
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Electrical fast transient waveform (switching circuit) load
I am simulating a circuit to model the EN 61000-4-4 waveform for electrical fast transients using LTspice. The idea is to have the generator for some in house testing.
Here is an old question I have ...
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Solenoid valve drivers
I'm developing a driver with a NMOS to control the solenoide valve.
The power supply V_uC is the signal from the board STM32.
As yoz can see from the schematic, I placed R2 to protect the STM32 pin. ...
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auto zeroing in comparator modelling
I am trying to model comparator with offset correction using auto zeroing method. Initially I am trying to model the ideal capacitor in LTspice. Here, I charge the top plate of the capacitor using ...
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Problems Comparator II of this CD4046 for LTspice
I downloaded a CD4046B model from user ale_t, which can be found here:
https://www.electro-tech-online.com/threads/new-spice-model-for-cd4046b-phase-locked-loop-ic.149093/
However, the Phase ...
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LTspice Bode plot is incorrect or inconsistent (op-amp circuit)
I'm testing the open loop transfer function of an op-amp circuit by following this schematic:
This is my LTspice schematic (keep in mind the actual op-amp circuit itself has been thoroughly checked, ...
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Loading problem with circuit simulation
EDIT #1
So I understand now the phenomenon that is happening.
Taking operational stage 2 Switch is OFF.
So there are the 2 cases discussed.
RL = ∞ (exaggerated scenario) the current I1 >> I2 ...
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Improvement in current sensor accuracy
I want to improve the accuracy of a current sensor. 49% of the error I have at the moment is from the tolerance of the shunt resistor and 26 percent of that it is from the op amp offset voltage.
How ...
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Why is my simulation getting stucked while doing .tran
I am trying to make a circuit with "ideal" thyristors (properties in the final), and I am getting the circuit simulation stuck at some point. I have -previously- solved this by adding a LP ...
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Ltspice: vary resistor
I wanted to simulate an LDR and a specific case where I have a bright LED using PWM.
This is the schematic:
I was changing the resistor as stated here which comes from a previous discussion ...
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LTspice Monte Carlo Analysis Clarifications required
I am learning about LTspice MC analysis from this site. I understood almost all the things except the below one.
"Then make another spice directive to execute a Monte Carlo run as below
.step ...
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LT spice simulation doesn't work. After a long time of waiting I see timestep too small error
So I was trying to recreate this circuit,
and only different thing are pins of that middle TL072 opamp. I have no clue how to do it properly so simulation would run.
you can download project here: ...
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Why am I not getting the expected simulation output in LTspice after adding bypass diodes to my PV module?
I am trying to simulate solar cells of a solar module with 72 cells and see the effects of partial shading and the activation of bypass diode. For now I am just simulating 2 cells of the PV module as ...
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Supplying and measuring from CT, different results in simulation and real scheme
I am implementing a scheme, which is supposed to supply constant current (showed as load resistance R12) and measure current from CT (CT is modeled as current source).
Here are additional zoomed ...
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how to find input impedance in AC analysis
I'd say that to find the input impedance, I simply have to add a trace that consists of dividing vi by Ii, which is the current ...
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LTspice: tables for parameterized passive components... why not?
What I'd really like is to be able to parameterize an impedance like a resistor against frequency with a table and interpolation in AC mode, as in Rf=table(freq,1meg,10,10meg,50)
I remember seeing ...
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Current Sensor accuracy Calculation
I wanted o calculate current sensor accuracy of 0 to 80A current detection circut showed in attached figure. I want to simulate in LTspice with diffrent values of reistance tolarences and this circut ...
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Chaining NAND gates does not work and results in wrong simulation with LTspice
I started building basic logic gates. I wanted to start basic and understandable so I started building some NAND gates just using two transistors. On its own hooked up to a switch and a LED they work ...
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AC Op-amp integrator with DC Gain Control in LTspice
Our teacher explained to us that this set up allows us to produce the effect of a low pass filter:
I have indeed found useful formulas to achieve this.
The problem however is that when I simulate ...
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Measuring voltage amplitude in LTspice
Isn't there an easy way to get the precise voltage amplitude from a graph signal after a .tran operation in LTspice?
The only thing I found are moving the cursor manually on the graph or entering a ...
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Three-stage boost converter improvements [duplicate]
Here is a three-stage boost converter that I simulated in LTSpice.
I am getting the high voltage output that I desire (1.3 kV). Before I proceed to the design phase, I would like to discuss a few ...
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Three-stage boost converter + Improvements
EDIT
As mentioned in the comments, a realistic load for me would be from 1 kΩ to 100 kΩ. I also was using damping resistors at each stage but it was pointed out to me that they are not needed, so here ...
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I need to develop a power source that delivers adjustable currents in the pA range
The task is to develop a power source that delivers adjustable currents in the pA range.
I need it from my circuit. Also it has to be a consistent power supply.
Here is my circuit.
This is with the ...
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Create .step list based on another parameter
Problem:
I'm trying to create a .step list of values based on another parameter but none of the syntax I've tried seems to work.
Example:
In the voltage divider ...
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Nexperia spice mosfet modell not working in LTspice
Hello I get errors with MOSFET spice models from Nexperia,
I've tried to include the spice fil within the asc and as .include to the lib, the error is the same.
I think it may be so that the spice ...
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Alternate between 0 and 180° shift at regular intervals for a sine source during a .tran operation on LTspice
Is it possible to alternate between a 0 and 180° shift at regular intervals (say every second) for a sine source in a circuit during a .tran operation in LTspice? (I need to see the reaction of my ...
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How to simulate sigma-delta ADC pulse train in LTspice
I am trying to simulate a complete current sense path of a motor phase, right from the shunt resistor to the MCU in LTspice.
We are using an AMC1303 (50 mV differential)(MPN: AMC1303M0520DWV) sigma-...
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I am simulating an equivalent model of a laser in LTspice shown below. I am supposed to plot the power at node Pout versus the input current
The issue is I am not able to plot the power without adding the load resistor which is not specified in the equivalent circuit.
Is there any other way to plot the power? If not, then what value of ...
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Differential pair simulation on LTspice using a transmission line
I'm trying to see how a long transmission line behaves by playing with its parameters in LTspice. The input signal is differential, but the output does not seem to be.
So I created the following ...
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Understanding LTspice curly brace substitution
I am trying to get my head around the specific details of how to use curly braces in LTspice. My end goal is to have a random value be generated and used before the start of a simulation for e.g. a ...
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Delay for low-pass filter to give proper mean value of a periodic signal on LTspice
I noticed that I have a 4-5 seconds delay before the output of my low pass filter op amp gives the correct mean value of an input square wave. Is it normal for the delay to be that long and if so, are ...
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LTspice - Type II compensation with UniversalOPamp2
I have some troubles with LTSpice for simulating a Type II compensation network. Here is the simulation:
Here is the result for the ideal opamp and for the non ideal opamp (UniversalOpAmp2):
The ...
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THS7001 PGA input voltage drop issue
I am having issues simulating the THS7001 programmable gain amplifier (PGA). I have the following setup:
I added a voltage divider at the input R11/(R10+R11) = 0.5, and configured the pre-amp stage ...
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LTspice can't find definition of model
I am trying to simulate the TPS54331 in LTspice, and I keep getting a "Can't find definition of model MBR340" error message when I run the simulation.
It looks like the MBR340 is a sub ...
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Mean value of square signal between 0 and 15 V in LTspice
I would like to get a signal that is the mean value of a square signal going from 0 to 15 V using an integrator op-amp. Here is what I'm getting so far (the op-amp I have put is the UniversalOpAmp2):
...
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Pulsating DC voltage [closed]
I am working on designing a circuit that generates a pulsating DC voltage into a 50 Ω load.
EDIT
Here is the circuit in question, i modified the circuit, I put R6, in order to get the same circuit ...
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Crystal resonator characterization in frequency and time domain
I want to measure a 32.768 kHz crystal resonator (not oscillator) in the frequency and the time domain using a ZURICH HF2LI instrument, which is a network analyzer and oscilloscope in one unit.
The ...
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Asynchronous SR DFF positive edge triggered [CMOS, SPICE]
I have been following some reference designs from Texas Instruments and Nexperia, and have been trying to replicate a model in LTspice (I am aware of the one in LTspice's library, but I would like ...
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TINA in LTspice [duplicate]
I need ADS8321 for LTspice. I used TINA-TI and when I download it, this is what I get.
What should I do? I can't use this as a library.
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Download ADS8321 in LTspice
How can I download ADS8321 in LTspice? If it's not possible, can you suggest an alternative?
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LTspice gives me strange wave form when I choose from 9.995s to 10s
Here is the diagram.
Here is the strange wave form given by Ib(Q1)
The following is the Spice netlist
...
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Two R2Rs with different widths in parallel
There's LVC16374, it has 16 output pins. In one configuration I need 3 DACs 5 bits wide each, in another configuration I need 2 DACs 7 and 8 bits. I use R2R circuits for DACs.
I was hoping here's a ...
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Problem with flyback converter simulation
I am simulating a flyback converter working in CCM and I don't understand the results. According to volt-second balance, there's this well-known equation regarding flyback converters:
$$V_{\mathrm{in}}...
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Circuit simulation for electrical fast transient generator
I am simulating a circuit using LTspice. It is a circuit that I am trying to model after the EN 61000-4-4 waveform for electrical fast transients. The idea is to have the generator for some in house ...
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Fourth-order passive filter not behaving as intended
I have been designing a passive 4th-order RC low-pass filter in LTspice and was surprised to see that the slope is off substantially from what I would expect for a 4th-order passive filter. Instead of ...
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AC analysis of SMPS shows instability. How to modify the analysis to reflect the transient stability?
Background
I have designed a switch-mode power stage with voltage-mode control that uses an LCLC filter in its output to obtain a very low ripple output voltage.
I have empirically arrived at a ...
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P-channel MOSFET is always on (LTspice)
I've modelled an undervoltage lockout circuit that should trip when the voltage is around 7 V. Attached is an image of the circuit.
At 12 V, the positive end of the comparator is less than the ...
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What is wrong with my op-amp circuit in LTspice?
I am revisiting the topic of using LTspice for the design and analysis of electrical circuits after a hiatus of a few years.
I am creating a gain block based off an example in the textbook "SPICE-...
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Can't simulate RC in LTspice
I am trying to learn LTspice. I have drawn a simple RC circuit and the probe-cursor is currently at the node connecting the cap and the resistor (Vc) (cursor image is not captured by PrintScreen).
I ...
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Can I model a diode with higher than usual junction voltage in LTspice using the "Eg" and "Vj" parameters?
I want to model a GaN transistor and include a diode to simulate its reverse conduction above ~2 V with an adjusted diode using the following model statement:
...
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