We reuse the components of the previous buck converters but change the topology inside the DC-DC converter.
Select the line between the ConstantPWN and the MOSFET by left-clicking it (step 1). Click the Delete key on the keyboard to delete this line. Left-click and draw the cursor to select the MOSFET and the diode at the same time (step 3). Left-click the selected area and hold down the mouse to move them to another area (step 4).
Left-click the inductor and move it to its own left side (step 1). Make sure that the inductor is well-connected to the DC source (step 2).
To change the direction of components, right-click the diode (step 1) and select 180 degrees (step 2). Make sure the cathode of the diode is toward to the load (step 3) and click OK to save the setting (step 5).
Left-click the diode with 180 degrees and draw it to connect to the inductor of the load (step 1). Make sure the resistor is showed as below (step 2). Right-click the MOSFET (step 3) and change its direction (step 3) to 90 degrees (step 4). Make sure its direction is shown as below (step 5) and click OK to save the setting (step 5).
Move the MOSFET back to the electric circuit of DC-DC converter (step 1) by left-clicking it and draw it to connect to the inductor and the diode (step 2). Connect the MOSFET and the ConstantPWM (step 3). The parameters of the ConstantPWM are the same as the previous buck converter.
Click the shortcut of start simulation (step 1) and see the simulation result shown in the scope. Right-click the scope (step 2) to see the details of the result. Here we can see the DC source has a voltage level 10 Volts and the output voltage of the converter is about between 15 and 20.