PCB Tech - PCB design to place components in the circuit schematic

Getting started with PCB design: placing components in circuit schematics

The first type of components to be placed in the circuit diagram are transistors, Q1 and Q2.

1. Select View>>Fit Document to display the schematic diagram layer in full screen.

2. Use the Libraries shortcut key to display the library panel.

3. Q1 and Q2 are BJT transistors, so select Miscellaneous Devices.IntLib from the library drop-down list at the top of the Libraries panel to activate the library.

4. Use filter to quickly load the required components. The default asterisk * can list all the components that can be found in the library. Setting the filter to *3904* will list all components that contain text 3904.

5.2N3904 will select the component 2N3904, and then click the Place button. Or, double-click the file name of the component directly. The cursor will become a crosshair and a triode will be close to the cursor. It is now in the placed state. If you move the cursor, the transistor will move with it.

6. Before placing the device on the schematic, its properties should be set first. When the transistor is attached to the cursor, click the TAB key to open the Component Properties property box.

7. In the Properties dialog box, enter Q1 in the Designator column.

8. Next, PCB practitioners must check whether the component package symbolizes the requirements of PCB. Here, the integrated library used has already included the packaged model and simulation model circuit. Confirm that the package TO-92A package model is included in the module. Keep the other options as the default settings, and click the OK button to close the dialog box.

Now start to place the device:

1. Move the cursor to place the transistor on the left in the middle. Click the mouse or press the ENTER key to complete the placement.

2. Move the cursor away, the transistor will appear on the schematic diagram, and it is still in the state of placing the device, and the transistor is still attached to the cursor. The function of Altium Designer is to allow deduplication of the same device. So, now place the second transistor. Since the transistor is the same as the original one, there is no need to edit the properties of the device again when placing the device. Altium Designer will automatically add the number suffix in the name of the designer. So the designator of the transistor placed this time will be Q2.

3. Found that Q2 is actually a mirror image of Q1. Change the direction of placing the device by pressing the X key. This will flip the component in the horizontal direction.

4. Move the cursor to the right of Q1. In order to make the position more accurate, click the PAGE UP key twice to enlarge the screen. So you can see the grid lines.

5. Click ENTER to place Q2. Every time a triode is placed, another triode that is ready to be placed will appear.

6. After all the transistors are placed, you can exit the placement state by clicking the right button or pressing the ESC key. The cursor returns to its original appearance.

Next place four resistors:

1. In the library panel, activate the Miscellaneous Devices.IntLib library.

2. Set filter to res1.

3. Click Res1 to select the device, so that a resistor element symbol will be pasted to the cursor.

4. Press TAB to edit the attributes. In the properties dialog box, set the designator to R1.

5. Make sure AXIAL-0.3 has been included in the list of model blocks.

6. The content of the PCB component is mapped by the schematic, so here and set the size of R1 to 100k.

7. Since simulation is not required, the Visible option in the Value parameter is set to be disabled.

8. Press the space bar to rotate the resistor 90°, in the correct direction.

9. Place the resistor on top of Q1 and press ENTER to complete the placement. Don't worry about how to connect the resistor to the transistor, it will be explained in the connection part.

10. Next place a 100K resistor R2 on top of Q2. DesigntorDesignator's label will automatically increase.

11. The size of the remaining two resistors R3 and R4 is 1k. Use the TAB key to set their CommnetComment to 1k, confirm that the Visible option of Value is disabled, and click the OK button to close the dialog box.

12. Place R3 and R4 as shown in Figure 6-1, and exit by right-clicking or ESC.

Now place two capacitors:

1. Capacitor devices are also in the Miscellaneous Devices.IntLib library, which has been selected.

2. Enter cap in filter in the component filter area of the Libraries panel.

3. Click CAP to select the device, click PLACE, so that a capacitive component symbol will be pasted to the cursor.

4. Use the TAB key to set the capacitance properties. Set disigatordesignator to C1, Comment to 20n, Visible to disable, and PCB package to RAD-0.3. Click OK. Just like setting the resistance, if simulation is needed, you need to set the value of Value. No simulation is needed here, so Value is set to disable.

5. As before, place the capacitor.

6. Exit by right-clicking or ESC.

The last device to be placed is the connector, located in Miscellaneous Connectors.IntLib.

1. In the library panel, select the Miscellaneous Devices.IntLib library. The required connector is 2 rows of pins, so the filter is set to *2*.

2. Click Header 2 to select the device, and click PLACE. Use the TAB key to set the capacitance properties. Set disigatordesignator to Y1, Visible to disable, and PCB package to HDR1X2. Click OK.

3. Before placing, press the X key to make the device in the vertical direction. Then place the connector device.

4. Exit placement.

5. File>>Save to keep the schematic.

All PCB components have now been placed. Connect component pins. This is very important because it is not possible to connect the pins directly above the pins. If you want to move the component, click and hold, and drag the component to the position the user wants.