There are often cases in electronic circuits where input power is filtered by inductors, capacitors, and resistors before it gets to the powered device of interest. In such cases, there are often nets with system-generated names created between the filter components and the powered device. While it may not be important purely from the point of view of the schematic to designate these nets as power nets, many downstream processes are facilitated by knowing that they are in fact power nets and not just some other default net with no special properties.
For example, trace width and voltage drop may be a concern to the layout designer. In-Circuit-Test programmers would want to know all the power nets because they’d want to verify the value of a series resistor or to ensure that an inductor is not either open-circuited or shorted.
The problem is that the task of naming all those power subnets is boring, tedious, time-consuming, and error prone. A perfect candidate for an automated process.
ExactCAD’s Change Power Subnet Names tool does exact that. It takes the power net name coming from the circuit’s power tap, and the reference designators of the series components in the circuit that create the power subnets, and uses them to create meaningful net names for the power subnets.
Using the tool is a simple process of selecting the components and nets of interest, running the tool, then checking off the nets whose names will be changed. The net names are then changed.
Here’s an example of the process:
See the power subnets connected to +3.3V2 by way of L10 and L15:
Select the components and nets:
Run the tool. Notice that the selected components and nets are shown, and new net names are suggested based on the power net name and the reference designators of the series inductors:
To complete the operation, the ‘Change Net Names of Selected Nets’ button is pressed and the net names are changed.
(Note that in this example, if the user wanted to have the net between L10 and C94 reference L10 instead of L15, the process could be done in 2 steps instead of one. The choice of L15 over L10 as the designator used in the net names, when both are possibilities, is arbitrary.)
This process only requires a few seconds and a few mouse clicks to complete. The tool conveniently stays on top of the DxDesigner window so that the user doesn’t have to keep jumping back and forth between applications.