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I'm working on a PCB. As ECAD software I am using KiCAD. All ICs will get two decoupling capacitor. One 100n ceramic and a 10uF electrolytic. Decoupling capacitor for OP Amp

For now I place them like shown in the picture at each OP Amp or IC.

My questions starts now: Since all capacitors share the same net, how can I make sure that the reference designator in the schematic later mach up with the physically placed capacitor in the layout. Is there any other way then looking them up in the schematic and then search for the right capacitor in the layout? Or is best practice to place them and later rename all components with this external tool for Kicad. LINK

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    \$\begingroup\$ Your C38 looks upside-down \$\endgroup\$
    – calcium3000
    Commented May 29, 2018 at 17:40
  • \$\begingroup\$ Also, what are you looking for? For example, for U11, would you want C11a, C11b, etc.? Or would you want the rats nest lines in PCBnew to point to the IC instead of the closest component on the net? \$\endgroup\$
    – calcium3000
    Commented May 29, 2018 at 17:44
  • \$\begingroup\$ Yes capacitors are upside down. Didn't noticed since now. Thanks. Yes the cap should point to the IC and not to the closed point in the net. \$\endgroup\$
    – Sorkfa
    Commented May 29, 2018 at 18:22
  • \$\begingroup\$ I am not familiar with KiCad, but could be specify a Room for each IC and its two Caps? \$\endgroup\$
    – Tyler
    Commented May 29, 2018 at 23:37
  • \$\begingroup\$ I'm working on that, but it won't be ready for version 5. The general idea is to auto-define a net tie between the power rail and a net that contains the cap and the power pin, so the ratsnest line connects them even if other pins are closer. \$\endgroup\$
    – Simon Richter
    Commented Jun 1, 2018 at 18:03

1 Answer 1

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One KiCad workflow for this is to to use the Get and Move hotkey in pcbnew (Default 'T'). Type in your reference designation and place the footprint.

KiCad version 5 will also group your initial import by sheet, so if you use hierarchical sheets, the capacitors will be physically close to your op-amp on first import.

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  • \$\begingroup\$ But with this workflow I still need to look up the reference designation in the schematic, type it in and place the component to the corresponding IC. I would like to have a way where each capacitor point directly to the IC. \$\endgroup\$
    – Sorkfa
    Commented May 30, 2018 at 5:58
  • \$\begingroup\$ Do you mean that the ratsnest line points to the IC? \$\endgroup\$
    – Seth
    Commented May 30, 2018 at 18:16
  • \$\begingroup\$ Yes. So Ist can identify which decoupling Capacitor belongs to the IC. \$\endgroup\$
    – Sorkfa
    Commented May 30, 2018 at 19:29
  • \$\begingroup\$ The easiest way is to place all of the grouped components in a subsheet. Then, when annotating, have eeschema use "Sheet number X 100" for the numbering. The subsheet components will also be placed next to one another when importing into pcbnew \$\endgroup\$
    – Seth
    Commented May 30, 2018 at 22:45
  • \$\begingroup\$ Great! If it works for you, please mark the answer accepted by clicking the check mark on the left of the answer. \$\endgroup\$
    – Seth
    Commented May 31, 2018 at 17:08

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