Regardless how many PCBs I design, I always find myself having to regularly review network paths on schematics layer and trace routes on PCBs. The complexity reminds me of a maze where only one path is the right one for a particular network. It is imperative that all the connections are accurate as errors made here will come back to haunt you later in the form of extensive PCB manufacture times due to redesigns or additional costs if boards have to be redone.
The best way to ensure network accuracy is by isolating it so that each connection can be visually verified and edited, if necessary. Without a robust software design tool, creating and editing schematics and PCB footprint can be quite difficult and time-consuming. On the other hand, with the right PCB design software, functionality and capabilities the design process can be greatly simplified and the time required to generate design files significantly reduced.
Altium Designer is a robust unified design environment for creating schematics and PCBs. This software package is designed to simplify the functional design tasks so that the hardest part of the process is the creative aspect, which lies with each individual designer. One of the capabilities that facilitate this for the designer is the ability to isolate and evaluate individual networks for accuracy. Highlighting nets will help you simplify your schematic and PCB design.
Using Highlight Nets in Altium to Simplify Schematic Design
Although the schematic does not provide the layout that will be present on your manufactured board, it is essential that it is accurate and complete. In all but very limited cases, such as when you are adding a component to a previous design or if the layout is quite simple, your PCB design will usually begin with the creation of the schematic. Here you can define all of your components and create your nets, as shown in the phase locked loop (PLL) circuit below.
Schematic example without highlighted nets
This circuit is laid out well and the network paths are readily visible at normal viewing. However, you are not able to clearly see whether all of the capacitors in the bank at the top are actually connected to the net since you cannot make out the nodes. One way to verify this would be to zoom in and enlarge the view. This is an option that can be used sometimes if you can keep the entire net within the enlarged view.
If not, then you cannot be sure which pins on the IC are connected to the net. Another option is to select and highlight the net while maintaining the same view. This allows you to check the IC and capacitor connections simultaneously, as shown below.
Schematic example with highlighted nets
This view gives you the information needed and a clear view of the entire circuit. Moreover, properties information about the net or wire itself is available in the panel at the right. This is a simple and easy way to verify the net and its connections.
Highlight Nets Simplifying PCB Design Too
Today, most PCBs are comprised of densely packed components in a small area. More often than not, these boards contain SMDs and multiple signal layers, as shown in the example below. It is virtually impossible to accurately follow any trace for this layout without help. Fortunately, Altium Designer provides help in the form of the ability to highlight nets even when they extend to multiple layers.
PCB example without highlighted nets
From the PCB editor panel, which is accessible by first clicking on the Panels tab at the bottom right of the window, individual or multiple nets can be highlighted. This gives you the ability to simultaneously inspect groups of nets if desired.
Instead of going through the Panels tab, you have the option to highlight nets by simply hovering over them. This option can be set using the Board Insight Display, which can be accessed from the Preferences menu under the PCB Editor options. With this option set, you can quickly go from net to net verifying connections by simply moving the mouse.
Ensuring that your printed circuit board design, schematic and board layout, is connected correctly is critical to the successful fabrication and assembly of your PCB project layout. Sending your design out with incorrectly-routed or misconnected nets is detrimental to your product development. Extended turnaround time and extra cost are but two of the penalties that you could face. These can be avoided by utilizing the ability to highlight nets.
PCB example with highlighted nets
In Altium Designer, there are multiple options that enable you to leverage this capability to simplify the verification of connections and circuit paths and make sure that the design you send to your manufacturer accurately reflects the printed circuit board you need built.
Although, Altium Designer is a robust software package with advanced capabilities, creating schematics and PCBs can be simple and easy. The program’s unified design environment and extensive functionality provide you with many tools to simplify your design experience. For example, the power distribution network analyzer, PDNA, allows you to test your nets, collectively or individually, during design. If changes are required, they can easily be applied to both your schematic and PCB. And the ability to highlight nets on your schematic capture and traces on your PCB make design changes quick and easy.
For more information on how to highlight nets for your schematic library and PCB design, contact an Altium PCB design expert
About the Author
PCB Design Tools for Electronics Design and DFM. Information for EDA Leaders.More Content by Altium Designer