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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.

Anything related to LTspice. LTspice is a SPICE simulation, schematic capture, and waveform viewer program from Linear Technology.

LTspice is completely free and has no limitations (no maximum number of parts, for example, like the free crippled versions of other commercial simulators). It is one of the best simulators around (it is used by Linear Technology for in-house simulations - it is no toy). The program is lightweight (~40 MB installed), works under Windows, and was developed to be run in Linux under WINE. The license is very liberal: you can even use it for commercial purposes without permission from Linear Technology, as long as you are not a competitor in the market of chip design and manufacturing.

See also:

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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 voltage supply.
josef.van.niekerk
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How to view and customize beta of a transistor in LTspice

If I need to set beta to a custom value, is it possible to make a customized transistor with a beta of my choice? In other words, can I edit a ready or generic transistor's beta and save it as a custom transistor? How can I do that?
user1245
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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 k\$\Omega\$ Sim. 2: R1 = 1 M\$\Omega\$, R2 = 10…
sebascarra
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How to plot "voltage drop" across a specific component in LTSpice?

In the above circuit I can only be able to plot |Vr1+Vc1| = V1 in green plot and Vc1 in blue plot. I use the voltage probe in LTSpice and click on the lines to obtain the plots. If I click on the line between V1 and R1 it plots |Vr1+Vr2| = V1. If I…
user16307
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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, .param Vi=120 .param Po=100 .param Ro='(Vi*Vi)/(2*pi*pi*Po)' where Vi and Po are design parameters and Ro is being computed from the…
jkiv
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Is it possible to comment out a circuit in LTSpice?

Is it possible to "comment out" a circuit in LTSpice in the same way that it is possible to "comment out" a directive? Such that it is visible, but ignored during simulation. Example use cases: file with multiple subcircuits of which only some…
Jet Blue
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How to implement frequency sweep in transient mode in LTspice?

Below the sinewave generator SineAC outputs a fixed 1Vpp 200Hz sine wave in LTspice: This output goes to another circuit and I can see the output of the entire system in time domain at a particular set frequency, in this case 200Hz. But is it…
user16307
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Has LTspice been extended to support the modified-Chan, non-linear hysteretic model for coupled inductors (transformers)

I'd like to figure out how to simulate coupled, non-linear cores using the included modified Chan model in LTspice and I'm specifically interested to know if LTspice has ever been extended to support transformers, using the modified-Chan hysteretic…
jonk
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Measuring the hysteresis losses via LTspice

I simulated the B-H curve of a random transformer. I would like to compute the hysteresis losses per period by computing the area of the curve. I know how to time integrate a set of points via a spice directive ".meas" but I do not know how to…
Jess
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LTspice, time step too small, microchip operational amplifier

I am trying to simulate a LDO with Microchip MCP6001 operational amplifier in LtSpice. With other OA simulation is ok, but with all Microchip models, the same error: Time step too small; Initial timepoint: trouble with u2:nmi-instance m:u2:12 Here…
yo3hcv
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LTSpice: How to change x-axis (ac sweep)

I want to plot a Bode diagram. LTSpice automatically plots the results as a function of frequency. I would like to multiply the frequency by 2*π, in order to obtain the angular frequency. How can I modify the x-axis quantities?
Lisa
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LTSpice's ltline (lossy transmission line) symbol slowing down the simulation process. What can I do?

LTSpice has the element called Lossy transmission line (symbol name ltline): I tried to simalate a pretty simple schematic: R2,R3 and R4 resistors are for solve floating node problem. Simulation of this scheme is extremely slow (about 30us/sec).…
Roman Matveev
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Why does the LTspice Schmitt component have two inputs?

LTspice has a Schmitt component (schmitt, or schmittbuf) which has two inputs. The upper input seems to be the signal input. What does the other input do? I read the docs on it, but I am slightly confused. Can somebody tell me what the two inputs of…
lalala
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ltspice, simulate negative resistance, avalanche effect

I found some nice circuits here as a pulse generators http://cappels.org/dproj/simplest_LED_flasher/Simplest_LED_Flasher_Circuit.html The author shows some scope pics and films from real world.. working. But when simulated in LtSpice... does…
yo3hcv
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LTSpice: how to setup sinusoidal or exponential voltage source?

My textbook proposes to calculate power for the voltage source which has sinusoidal or exponential waveform. Probably my question is very silly, but I really don't know how to input textbook's equations using LTSpice independent voltage source setup…
tenghiz
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