If you do not have LTSpice already installed on your machine, please head over to LTSpice's page on Analog Device's website (Link: LTspice Information Center | Analog Devices).
Note: a video version of this tutorial is available here
Click on the applicable download button that suits your machine's operating system.
Upon successfully downloading and launching LTspice, you will be greeted with a window that looks something like in the figure below.
Alright, now we will need to create a new schematic. That can be done by either of the following approaches:
- click on File then choose New Schematic.
- click on the New Schematic symbol
on the toolbar. - on your keyboard, press Ctrl+N.
Upon doing so, a new grey-ish screen will pop up... that will be your new empty schematic (just like the one in the figure below).
In this example, we will try to design and simulate a very basic voltage divider.
To recap: a voltage divider is a circuit that takes a certain input voltage then lowers it by utilizing two resistors in series.
For example: I want to design and simulate the voltage divider I have drawn below.
Where:
- Input voltage (Vin) is 5V
- First resistor (R1) is 1k ohm
- Second resistor (R2) is 2k ohm
- Vout is the output voltage which will be figured out during our simulation, but can also be calculated using the following equation:
We will be following the steps below:
- Step 1 - add a voltage source and ground
- Step 2 - add two resistors in series
- Step 3 - wire all the components
- Step 4 - assign voltage and resistance values
- Step 6 - add an output connection point (Net) named Vout
- Step 7 - Simulate the circuit
Adding a Voltage Source (Vin) and Ground (GND):
To add a voltage source: either click on the voltage source symbol 
on the toolbar or press V on your keyboard.
on the toolbar or press V on your keyboard.Move the cursor across the schematic and place it wherever you like by clicking on the Left Mouse Button. Note: while the symbol is still hovering, you can press Ctrl+R on your keyboard to rotate the symbol, and you can press Ctrl+E to mirror it (flip it horizontally).
MOVING A SYMBOL: Press M on your keyboard then left click on the symbol you want to move, move it around and left click when you where you want to place it.
DELETING A SYMBOL: Press DEL on your keyboard then left click with your mouse on the symbol you want to move.
ZOOMING IN AND OUT OF THE SCHEMATIC: Scroll up on the scroll wheel of your mouse to zoom out and scroll down to zoom in.
To add ground: either click on the ground symbol 
on the toolbar or press G on your keyboard.
on the toolbar or press G on your keyboard.Note: you cannot rotate the ground symbol.
Adding Two Resistors in Series and Wiring Components:
To add a resistor: either click on the resistor symbol (highlighted in figures below) on the toolbar or press R on your keyboard.
Place one resistor below the other.
on the toolbar or press W on your keyboard.After wiring your circuit, it will look something like the following:
Assigning Values to Components:
To assign a value to component, you will need to right click on it.
Let's start with the voltage source which we will be assigning 5V to it. When you right click on the component, a window will pop up allowing you to enter the value as shown below. Once you have entered the value, click on OK.
Next, the resistors:
- for R1 we will need to enter either 1000 or 1k
- for R2 we will need to enter either 2000 or 2k
Adding an Output Connection Point (Net):
While this may not be necessary for a small circuit like this, I usually like to use nets to highlight certain points in the circuit which will allow me to easily probe them when I am running simulation.
Between R1 and R2, I will branch out a small wire to the right. Then, I will either click on the net symbol 
or press N on keyboard. A small menu will pop up, it will look like the following:
or press N on keyboard. A small menu will pop up, it will look like the following: 
Change the Port Type to output, and in the empty field type 'Vout'. Click on then attached net to the branched wire between R1 and R2.
Your final circuit should look something like this:
OOOOOR, if you want to use two separate Ground symbols, it will look something like this:
Alrighty, it is to simulate this circuit.
Simulating the Circuit:
We will be performing DC Operating Point Analysis (.op) simulation, a type of simulation that is used to determine the steady state (DC) behavior of a circuit under constant input.
Part 1 - Configuring the Simulator which can be done by either of the following:
- Click on Simulate, then Configure Analysis
- Click on the Configure Analysis symbol
- Press A on your keyboard to bring up the configuration window.
On the Configure Analysis window navigate to the DC op pnt tab, then click Ok and place the .op syntax somewhere on the side.
Part 2 - Running the simulation which be done by either of the following:
- Click on Simulate, then Run/Pause
- Click on the Run/Pause symbol
- Press Alt+R on your keyboard.
Once you do so, a new window with your simulation results will pop up.
You can also try to probe around the circuit if you like.
Close the result window then start hovering over circuit components, you will start to see information related to current and power dissipation on the bottom left of the window
You can also try to place voltage probes around to display the voltage values across various points. That can be done by left clicking on the part of the circuit you want to probe
For example: I am going to place a probe before R1, another one before R2, and a third probe next to ground for funsies.
There you have it!
I will probably make a video version for this for those who don't feel like reading and rather watch.