Handling Power pins

Coming from PADs also I’d like to see Kicad rework the handling of power pins for a part in the schematic. Most schematics that one sees do not show power and ground pins on most/many components. Showing them clutters up the schematic. Admittedly I am new to Kicad and there may well be a better method than how I did it.

For example, I was using a dual opamp. In the Kicad system I found I had to iinclude 3 “units”: unit (amp) A, and unit (amp) B. Fair enough. But then there’s a 3rd unit C, which was just the Vcc and gnd pin. I may be uninformed, but I found I had to include a unit C (two pins) on the schematic. I thought maybe I could at least hide those pins but I didn’t find a way to do that.

Hello @swr999

I moved your comment to a new topic as you are discussing Power Pins on ICs (mainly). The previous topic was discussing Power Symbols. eg Vcc, GND, +5V etc.

My own thoughts are that I like this system. IC power pins are on a PCB layout so they should be included somewhere on a schematic. This Kicad system gives the user a choice of either attaching the power pins unit to a functional unit, or placing them out of the way of the main schematic sheet, maybe in an unused corner, or on an entirely different sheet, perhaps dedicated to all the symbol power pins of that schematic.

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I to am very familiar with PADS. The power pins should be either listed as part of the op-amp or as a descrete power symbol. It should not be left off of the schematic. I wouldn’t consider it clutter.

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Thanks for the replies!
Yes, I agree, power pins should be included in the schematic. Just that my preference would be for them to be optionally hidden for any particular part on the schematic sheet .

I find them only slightly annoying. But still essential. Yes, they might clutter the schematics. So I always move them out of the way, all into one corner, together with PWR_FLAG if necessary. For me, that looks very tidy and clear. Also, they give a hint during layout where the decoupling capacitors have to be placed. All at the chips and not to the power output.
During layout, my schematics is on the second screen. So a quick feedback of their purpose.

How you then see what power nets are connected to that IC?

Even I don’t do it that way I think it is a good solution in most cases.
But nowadays when each CMOS output can source 20mA or more and CMOS IC need zero, zero, nothing power supply current, you can switch on/off parts of your device by simply powering it from microcontroller pin. If such solution is used the better is to have power pins where they are used.
So the library defined that way that you can use power part separately or place it at one of opams / gates / flip-plops is the best solution, I think.

These are all good, thoughtful comments well worth considering. Thank you all!


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