LTspice
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LTspice
Free – Fast – Unlimited
Demo
•
BMS Demo
•
Silent Switcher
•
Trinamics Motor Control
•
GMSL
•
Smart Helmet
3
©2025 Analog Devices, Inc. All Rights Reserved.
New LTspice Platform
LTspiceXVII
LTspice 24.1 latest
To check Version
Improved Simulation speed
(ADI-standard Dell i7 Precision 5550 laptop)
New Feature in LTspice 24.x.x
4
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New LTspice Platform
Improved UI scaling on Large Monitors
•
DPI awareness
•
New Icons scale cleanly
•
Clearer Icon functionality
► New default background
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► Improved component selection dialog
▪ Cleaner, more efficient layout
▪ Better in-dialog component search
▪ Quick links to analog.com
Getting Started with
LTspice
analog.com
analog.com
LTspice
Free – Fast – Unlimited
Topics
•
What is LTspice?
•
Basic RC Circuit Analysis
•
DC-DC Converter - Analyzing Circuit Performance
•
DC-DC Converter - Simulating a Transient Response
•
AC Analysis
•
Defining Parameters
7
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What is LTspice?
LTspice
Free – Fast – Unlimited
8
©2025 Analog Devices, Inc. All Rights Reserved.
What is LTspice?
ADI’s analog electronic circuit simulator
• Free
Even though LTspice is freeware, it
outperforms many pay-for options
• No cost simulation platform designed for our customers and the engineering community
• *Not* licensed for use by semiconductor manufacturers
• Unlimited
• Draft and simulate circuits of unlimited size and content
• Unlimited hierarchy are supported
• Fast
• Optimized macro-models for many ADI devices
•
9
E.g. switch mode power supplies simulate rapidly
©2025 Analog Devices, Inc. All Rights Reserved.
How Do I Get LTspice?
Go to www.analog.com/LTspice
Site also contains useful links to:
• Demo Circuits (reference designs)
• Documentation
• Handout of shortcut keys
• Video Tutorials
• Technical Articles
10
©2025 Analog Devices, Inc. All Rights Reserved.
LTspice is a standalone application
that runs on your computer
How Do I Get Started Using LTspice?
Use one of the 1000’s of Demo Circuits available at analog.com
•
Reviewed by product application engineers
Use a test fixture
•
Provides a good starting point
Create your own using the schematic editor
•
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With Basic RC Circuit
©2025 Analog Devices, Inc. All Rights Reserved.
Demo Circuits Are Available on Product and Eval Board
Pages
Click on tool and
Simulation
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©2025 Analog Devices, Inc. All Rights Reserved.
How Do I Get Started Using LTspice?
Use one of the 1000’s of Demo Circuits available at analog.com
•
Reviewed by product application engineers
Use existing Examples in LTspice
•
Provides a good starting point
Create your own using the schematic editor
•
13
With Basic RC Circuit
©2025 Analog Devices, Inc. All Rights Reserved.
Use Existing Examples in LTspice
OR
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©2025 Analog Devices, Inc. All Rights Reserved.
How Do I Get Started Using LTspice?
Use one of the 1000’s of Demo Circuits available at analog.com
•
Reviewed by product application engineers
Use a test fixture
•
Provides a good starting point
Create your own using the schematic editor
•
15
With Basic RC Circuit
©2025 Analog Devices, Inc. All Rights Reserved.
Basics RC Circuit Analysis
LTspice
Free – Fast – Unlimited
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LTspice : Basic RC Circuit
A picture containing icon
Description automatically generated
Click CTRL+N or
New Schematic Icon
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Click File Tab and &
Select New Schematic
Adding Passives and Grounds
For Symbols use
R for Resistor
C for Capacitor,
L for Inductor,
D for Diode,
V for Voltage source,
G for Ground
Ctrl+R to rotate
before placement
Ctrl+E (echo) to
mirror before
placement
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©2025
To exit a symbol, select
Esc or right click
Wire Up the Circuit
N to Label the wire/net
W to draw a wire/net
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©2025
Wire Up the Circuit
Left-Click ground
“Pull” wire up through the source
Left-Click here
to anchor
Press the ESC key or
right click to stop
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©2025
“Pull” wire through the resistor
Left-Click here
to anchor
Add Net Labels
N to“Label Net”
Place on wire
Enter net name
Specify the name so an arbitrary
one isn't generated for the node
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©2025
Component Values
Right-click on
symbol
Or Right-click on
value
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©2025
Units for Component Parameters
M = m = milli = 10-3
U = u = micro = 10-6
N = n = nano = 10-9
P = p = pico = 10-12
F = f = femto = 10-15
K = k = kilo = 103
MEG = meg = 106
G = g = giga = 109
T = t = tera = 1012
Hints
 Use MEG (or meg) to specify 106, not M
 Enter 1 for 1 Farad, not 1F
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©2024 Analog Devices, Inc. All Rights Reserved.
©2025
Editing Components
Right-Click on the component to edit attributes
You can also edit the visible attribute and label by pointing at the text with the mouse (cursor will change
to a text icon) and right-clicking
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©2025
Component Database
Available for resistors, capacitors, inductors, diodes, bipolar transistors, MOSFET transistors, and JFET
transistors
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Voltage Source Parameters
Click
“Advanced”
Right-click source
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Voltage Source PULSE Parameters
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Zooming In and Out, Fit
Zoom to Rectangle
or Z
Zoom to Fit(space)
Zoom Out or Shift+Z
Zoom In or Out -> Scroll Wheel
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©2025
Drag & Move
Duplicate or
Ctrl + C
Move or M
Stretch Mode
or S
Right click and Draw
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©2025
Edit Simulation Command – Transient Analysis
Enter in
0.01
Select “Configure
Analysis” in
Simulate menu
Click to place
on schematic
Click OK
Performs the DC analysis to establish a DC operating point, then increments the time step and calculates
the voltage and current values of the respective nodes
Useful for start up, stability, and transient analysis
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©2025
Completed Schematic
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Summary of Shortcuts (Toolbar is Available in Windows Version)
Auto Range[Ctrl + Y]
Zoom to Fit [Space]
Zoom Back [Shift + Z]
Zoom In [Z]
Draw Wire [W]
Place Ground[G]
Place Voltage Source[V]
Place Resistor[R]
Place Capacitor[C]
Place Inductor[L]
Place Diode[D]
Place Library Part[P]
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©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Stretch Mode [S]
Move [M]
Duplicate [Ctrl+C]
Delete [Del or Backspace]
Place Spice Directive [.]
Place Text [T]
Label Net [N]
Toolbar is handy but
keyboard shortcuts are
more efficient
Rotate [Ctrl+R]
Mirror [Ctrl+E]
Undo [Ctrl+Z]
Redo [Ctrl+Shift+Z]
Serach [Ctrl+F]
Summary of Shortcuts (Toolbar is Available in Windows Version)
Toolbar is handy but
keyboard shortcuts are
more efficient
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©2024 Analog Devices, Inc. All Rights Reserved.
©2025
LTSpice : Basic RC Circuit
Click Wire or Net
LTspice_RC_Filter_
LTSpice_RC_Filt
Example.asc
er_Example.asc
Click for Capacitor
Click GND
Click for Resistor
Click Voltage source
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©2025 Analog Devices, Inc. All Rights Reserved.
LTSpice : Basic RC Circuit
Right click on the component to assign the values and other
parameters
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LTSpice : Basic RC Circuit
Click to configure
Simulation settings
Configuration
Options & Settings
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LTSpice : Basic RC Circuit
Click to Run or
Pause simulations
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Click Tab Simulate
And select Run/Pause
OR Alt + R to start the
simulations
LTSpice : Basic RC Circuit
Voltage(V1) plot
(GREEN)
38
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Voltage(V_RC) plot
(BLUE)
LTSpice : Basic RC Circuit
Current Plot
(GREEN & RED)
39
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LTSpice : Basic RC Circuit
Right Click on Plot Window to chose options
Change color or
Add plot Pane or
Add new traces or
cursors
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When Cursor clicked on any plot window,
There is Plot Setting Tab appears in the
Menu for additional Plot options
LTSpice : Basic RC Circuit
Place cursors to get the values
and timing for the respective
plot from the simulations
41
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DC-DC Converter Analyzing Circuit Performance
LTspice
Free – Fast – Unlimited
46
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Running a DC/DC Converter Simulation
A picture containing icon
Description automatically generated
LTC3412A_DC
_Load.asc
47 47
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©2025
Viewing Voltage Waveforms
Plot the voltage on any wire by Left-Clicking it
• Tip: All Demo Circuits have INs and OUTs clearly labeled to help you quickly select them
Click here for
output Voltage
waveform
48 48 ©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Labeling - Trick
Highlight net from waveform viewer
• Alt-Left-Click on the label in the waveform viewer (i.e. V(n006)) and it will now highlight that particular net on the schematic.
You can also use the search function ( )
Alt-LeftClick
Net
Highlighted
49 49 ©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Viewing Differential Voltage Waveforms
To create a measurement reference node, Right-Click on the desired node and select “Mark Reference”
• A black voltage probe is anchored to the selected node
All measurements in the circuit are now referenced to the node with the black probe
Hit the ESC key to remove the reference mark
50 50 ©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Viewing Differential Voltage Waveforms
Left-Click on one node and drag the mouse to another node
• Red voltage probe at the first node
• Black probe on the second
51 51
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©2024 Analog Devices, Inc. All Rights Reserved.
Viewing Current Waveforms
Plot the current through any component by Left-Clicking on the body of the component
•
Current flowing into a node is defined as being positive
Click here for
inductor current
waveform
52 52
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©2024 Analog Devices, Inc. All Rights Reserved.
Deleting Waveforms
Method #1: Right-Click on a trace label to be deleted
• Select “Delete this Trace”
• Deletes only the selected trace
53 53
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©2024 Analog Devices, Inc. All Rights Reserved.
Deleting Waveforms
Method #2: If the plot window is active hotkey F5 is equivalent
• Cursor turns into scissors
• Left-Click on one or more trace labels to delete. ESC to quit
54 54 ©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Left click
wavefor
m to
delete it
Deleting Waveforms
Method #3: Plot the same waveform twice in succession
• Deletes all but that waveform
Click,
click
55 55
©2025
©2024 Analog
Analog Devices,
Devices, Inc.
Inc. All
All Rights
Rights Reserved.
Reserved.
Zooming In and Out on a Waveform
In the waveform window, use the mouse to zoom in and out. Click and drag a box about the region you wish to see drawn larger
Using the toolbar, click on “Zoom full extents”, to zoom back out
Zoom Full Extents
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©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Measuring V, I and Time in the Waveform (Measure
using cursors)
Right-Click on the waveform name in the waveform window
For “Attached Cursor”, select “1st & 2nd”
2.
Position cursors to make desired
measurements
1.
57 57
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©2024 Analog Devices, Inc. All Rights Reserved.
3.
Measuring V, I and Time in the Waveform (Measure
using cursors)
Drag a box about the region you wish to measure
• Left-Click, drag, and hold
View the lower left corner of the window for the status bar. The dx and dy measurement data is displayed here.
Use Undo from the File menu or press “F9”
58 58
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©2024 Analog Devices, Inc. All Rights Reserved.
Viewing Wire Current Waveforms
Plot the current through any wire by Alt+Left-Clicking on the wire
•
59 59
An ammeter will appear to indicate that the wire current will be displayed
©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Average & RMS Calculations
Average & RMS Current, Voltage, or Power Dissipation
•
Calculated only for the visible area of the plot window
Click on inductor L1 to display the inductor current waveform
•
Ctrl+Left-Click the I(L1) trace label in the waveform view
Example:
Measure average and RMS current for
inductor in LTC3412A circuit. Zoom in as
shown for this waveform.
60 60 ©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Instantaneous & Average Power Dissipation
Instantaneous Power Dissipation
•
Alt+Left-Click on the symbol of the LTC3412A
•
Waveform is displayed in units of Watts
Average Power Dissipation and Energy
•
Click, hold, and drag in the waveform window to display waveform at
steady state
•
Ctrl+Left-Click on the Power Dissipation Trace Label in the
waveform view
•
Waveform summary window will appear which shows power
dissipation in the IC
Example:
Measure the power dissipation in the LTC3412A IC
61 61
©2025
©2024 Analog Devices, Inc. All Rights Reserved.
DC-DC Converter Simulating a Transient Response
LTspice
Free – Fast – Unlimited
62
©2025 Analog Devices, Inc. All Rights Reserved.
Current Load and Pulse Function
► You can simulate a load with a Resistor or Current (active) load
A picture containing icon
Description automatically generated
► In particular, the Pulse function with a current load is helpful for transient response analysis
▪ Steps a current load from one load value to another load value
63 63
©2025
©2024 Analog Devices, Inc. All Rights Reserved.
LTC3412A_DC
_Load.asc
Edit the Current Load to a Pulse Function
► Edit the .tran directive in the LTC3412A simulation to disable steady state detection
► Right-Click on the current load
▪ Select “Pulse”
▪ Modify the attributes (see below). Click “OK”
Forces current
to be zero when
voltage is zero
64 64 ©2025
©2024 Analog Devices, Inc. All Rights Reserved.
Run the Simulation for Transient Response
► Run the simulation
► Click on the OUT node to display Vout
► Click on the output current load to display Iout
► Notice the presence of the pulse load
► Use the application of the pulse load /
transient response to verify stability and
modify the compensation components, as
necessary.
65 65
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©2024 Analog Devices, Inc. All Rights Reserved.
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