Power pins

Hello, I just wanted to check that I am doing this correctly wrt inter-sheet power connections. There are three other sheets in the schematic, all using the same voltages etc. The picture below is from one of the sheets


Here is the top level schematic where the bulk voltages come in



All my schematics are single sheet and I’ve never even tried multi sheet schematic. I think that VCC and GND symbols you have there should be enough (provided you use them at every place that need to be connected to these nets.

I noticed that when I annotate the three sheets, it does all three without any problems, So I’m assuming the power interconnections across the sheets are also ok. I’m not getting any errors since adding the PWR_FLAG to each rail across the sheets.

Global labels always connect to each other on all sheets in a project they are used.

And the same for all power symbols. In KiCad V8 you can also edit the name of the power symbols inside the schematic, and this will create a new net.

Thanks for the clarification, Paul.

Why would you need global symbols if the standard power symbols connect across schematics sheets within a project?

I can imagine not only power nets connected globally. For example I²C bus lines can be such nets.
I don’t know what actions have to be taken to connect for example RS485 driver located on another schematic sheet to microcontroller at main sheet using local labels only. May be using RXD, TXD, TEN global symbols at main schematic sheet and at the one with RS485 chip is simpler.

As Piotr already mentioned, global labels can be used for signals that are used on a lot of sheets. I2C can be a good example, but also global clock or reset signals. If signals are used on only a small part of the schematic, it often makes more sense to route them though the hierarchy, so you can see where they are going.

Another fact is that a local label and a global label with the same name also connect on the same sheet. (But a local label does not connect with a global label on another sheet, even if it has the same name. One technique I’ve seen used is to always use local labels to connect on a sheet, and if that signal is also used on other sheets, then a (list of) global labels is placed somewhere on that sheet (for example in a corner). This gives a nice overview of all labels that connect to other sheets, and in combination with the inter sheet references, you can also see (and jump to) the sheets where they connect.

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