Digital components, even though they do not show the power and ground pins in the symbol (hidden pins), they are pre-configured to have the power and ground pins virtually connected to the schematic's global power and ground nets. As long as the nets exist somewhere else in the schematic, the IC power and ground pins will be connected.
You can check this behavior if you follow the next steps:
- Place the digital component on the work area
- Double-click the component to open the Properties dialog and select the Pins tab
- Look under the Nets column to view the assigned global net for each pin (for example, Pin 14 mapped to
VCC, Pin 7 mapped to GND). - (Optional) Double-click a cell under the Nets column to modify the net name if your schematic uses a different global power net.
- Click OK to close the Properties dialog
Display Pin Numbers on the Schematic Symbol (Optional)
If you need to visually display the physical pin numbers (for lab documentation or verification):
- Double-click the component to open Properties.
- Navigate to the Display tab.
- Select Use component-specific visibility settings.
- Check the Show footprint pin names checkbox.
- Click OK. Physical IC pin numbers will now appear next to the terminals on the schematic symbol.
Additional Information
General tips for digital ICs:
- As long as the net name exists anywhere on the schematic, the digital component is virtually connected.
- By default, digital components are connected to
VCC and GND or VSS and VDD, simply place the appropriate source symbol anywhere on the schematic to power up the IC. Select Place»Component, select Master Database, Sources Group and Power Sources Family. Locate the appropriate symbol in the Component field and place it in the work area.