For this introductory example, you will simulate a standard non-inverting operational amplifier circuit (shown in Figure 1). The gain of this non-inverting amplifier is calculated by the expression Gain = 1 + R1/R2. Therefore, if R1 = R2, then the gain is equal to 2, which you will verify when you run interactive simulation in Multisim.
Figure 1. Non-inverting amplifier circuit.
Begin by drawing your schematic in the Multisim environment.
Figure 2. Select a Component window.
The Component Browser organizes the database components into three logical levels. The Master Database contains all shipping components in a read-only format. The Corporate Database is where you can save custom components to be shared with colleagues. Finally, the User Database is where custom components are saved that can be used only by the specific designer.
Now place the remaining circuit components using the techniques discussed in the previous steps.
Figure 3. Selecting the operational amplifier.
Note that this component is a multisection component, as shown by the A and B tabs.
Note: you can rotate a component before placement by using the <Ctrl+R> shortcut on your keyboard when the component is ghosted to the mouse pointer.
Figure 4. Components placed on the workspace area.
Multisim is a modeless wiring environment. This means that Multisim determines the functionality of the mouse pointer by the position of the mouse. You do not have to return to the menu to select between the placement, wiring, and editing tools.
Figure 5. Wiring the schematic.
The last key step is to connect the power supply terminals to the positive and negative power rails of the opamp via a virtual connection using On-page connectors.
Figure 6. Schematic with On-page connectors.
You are now ready to run an interactive Multisim simulation; however, you need a way to visualize the data. Multisim provides instruments to visualize the simulated measurements. Instruments can be found on the right menu bar and are indicated by the following icons.
Figure 7. Instruments toolbar.
Figure 8. Connecting the Oscilloscope to the schematic.
Figure 9. Simulation results.
We are now ready to transfer the Multisim design to Ultiboard for PCB layout. In preparation for this we need to take into consideration that sources (power, signal) and ground are virtual components and, therefore, they cannot be transferred to Ultiboard. Also, all components must include footprint information. It is a good practice to replace power sources and ground with connectors.
Figure 10. Connecting the terminal block.
Figure 11. Schematic with terminal blocks.
Figure 12. Default board outline and parts transferred from Multisim.
For this exercise we will use a 2x2 inch board. Follow these steps to resize the board outline.
Figure 13. Design Toolbox.
The Layers tab of the Design Toolbox allows you to move between layers of your design and control the appearance of the layers.
Figure 14. Select toolbar.
The Select toolbar contains the functions used to control selection filters. In other words, these filters control what can be selected by the mouse pointer.
Place components inside the board.
Figure 15. Parts placement.
For this exercise you will place traces on both the Copper Top and Copper Bottom layers.
Figure 16. Placing a trace.
Figure 17. Routed board.
Figure 18. 3D Preview.
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