{
 "commit": {
  "sha": "73aa1ed796927a1d054d656ffd1e4acdce4d4b5e",
  "date": "2026-02-28T02:35:21+00:00",
  "subject": "cr(hw): use AMS1117-3.3 with 2x 10uF tantalum",
  "url": "https://github.com/DLehenbauer/econopet/commit/73aa1ed796927a1d054d656ffd1e4acdce4d4b5e",
  "board": "hw/rev-b/mainboard/kicad/Mainboard.kicad_pcb"
 },
 "project": {
  "title": "EconoPET mainboard (rev. B)",
  "repo": "https://github.com/DLehenbauer/econopet",
  "licence": "CC0-1.0"
 },
 "impactDiff": {
  "schema": "nativecad.impactDiff/1",
  "inputs": {
   "before": {
    "format": "kicad_pcb",
    "source": {
     "repo": "https://github.com/DLehenbauer/econopet",
     "sha": "5b45e41abc98e2212e44362cb5ed07eb2c4c8201",
     "path": "hw/rev-b/mainboard/kicad/Mainboard.kicad_pcb"
    }
   },
   "after": {
    "format": "kicad_pcb",
    "source": {
     "repo": "https://github.com/DLehenbauer/econopet",
     "sha": "73aa1ed796927a1d054d656ffd1e4acdce4d4b5e",
     "path": "hw/rev-b/mainboard/kicad/Mainboard.kicad_pcb"
    }
   },
   "optionsSha256": null,
   "engine": null
  },
  "layoutDiff": {
   "schema": "pcbDiff/1",
   "identical": false,
   "tolerances": {
    "posTol": 0.001,
    "rotTol": 0.01,
    "widthTol": 0.0001,
    "drillTol": 0.0001,
    "lengthTol": 0.0001,
    "areaTol": 0.000001,
    "thickTol": 0.000001,
    "routeTol": 0.01,
    "sampleStep": 0.1,
    "minPadOverlap": 0.6
   },
   "summary": {
    "components": {
     "added": 2,
     "removed": 3,
     "renamed": 0,
     "moved": 1,
     "rotated": 0,
     "flipped": 0,
     "footprintChanged": 0,
     "valueChanged": 1
    },
    "nets": {
     "added": 0,
     "removed": 1,
     "renamed": 0,
     "changed": 3,
     "rerouted": 3
    },
    "outlineChanged": false,
    "stackupChanged": false
   },
   "components": {
    "source": "explicit",
    "counts": {
     "a": 295,
     "b": 294
    },
    "added": [
     {
      "refdes": "C108",
      "footprint": "Capacitor_Tantalum_SMD:CP_EIA-3216-18_Kemet-A",
      "value": "10u 16V",
      "at": [
       311.169998,
       106.714999
      ],
      "rot": 0,
      "side": "front",
      "pads": 2
     },
     {
      "refdes": "C109",
      "footprint": "Capacitor_Tantalum_SMD:CP_EIA-3216-18_Kemet-A",
      "value": "10u 16V",
      "at": [
       311.169998,
       108.875001
      ],
      "rot": 0,
      "side": "front",
      "pads": 2
     }
    ],
    "removed": [
     {
      "refdes": "C16",
      "footprint": "Capacitor_SMD:C_1206_3216Metric",
      "value": "47u 10V",
      "at": [
       310.01,
       106.32
      ],
      "rot": 270,
      "side": "front",
      "pads": 2
     },
     {
      "refdes": "R6",
      "footprint": "Resistor_SMD:R_0603_1608Metric",
      "value": "0",
      "at": [
       312.704999,
       104.085
      ],
      "rot": 180,
      "side": "front",
      "pads": 2
     },
     {
      "refdes": "R8",
      "footprint": "Resistor_SMD:R_0603_1608Metric",
      "value": "0",
      "at": [
       312.704999,
       105.604998
      ],
      "rot": 180,
      "side": "front",
      "pads": 2
     }
    ],
    "renamed": [],
    "moved": [
     {
      "refdes": "R10",
      "from": [
       312.704999,
       107.795001
      ],
      "to": [
       311.14,
       104.28
      ],
      "delta": [
       -1.564999,
       -3.515001
      ],
      "distance": 3.847655637
     }
    ],
    "rotated": [],
    "flipped": [],
    "footprintChanged": [],
    "valueChanged": [
     {
      "refdes": "U3",
      "from": "TLV1117LV33",
      "to": "AMS1117-3.3"
     }
    ]
   },
   "nets": {
    "added": [],
    "removed": [
     {
      "name": "Net-(C16-Pad2)",
      "lengthMm": 3.392068482,
      "width": {
       "min": 0.5,
       "max": 0.5
      },
      "vias": {
       "count": 0,
       "drills": {}
      },
      "regionAreaMm2": 0,
      "pads": [
       "C16.2",
       "R6.2",
       "R8.2"
      ],
      "layers": [
       "F.Cu"
      ]
     }
    ],
    "renamed": [],
    "changed": [
     {
      "name": "+3V3",
      "length": {
       "a": 616.709519134,
       "b": 618.751237306,
       "delta": 2.041718172,
       "perLayer": {
        "F.Cu": {
         "a": 342.871601819,
         "b": 345.494881985,
         "delta": 2.623280167
        },
        "B.Cu": {
         "a": 273.837917315,
         "b": 273.25635532,
         "delta": -0.581561995
        }
       }
      },
      "width": {
       "min": {
        "a": 0.2,
        "b": 0.2
       },
       "max": {
        "a": 0.6,
        "b": 0.6
       },
       "perLayer": {}
      },
      "copperArea": {
       "a": 4.228987207,
       "b": 4.228987207,
       "delta": 0,
       "perLayer": {},
       "note": "pour (region) area only"
      },
      "vias": {
       "a": 23,
       "b": 23,
       "delta": 0,
       "drills": {
        "a": {
         "0.3": 23
        },
        "b": {
         "0.3": 23
        }
       },
       "drillDelta": {}
      },
      "pads": {
       "a": 100,
       "b": 101,
       "added": [
        "C108.1",
        "C109.1"
       ],
       "removed": [
        "C16.1"
       ]
      },
      "reroutedLengthMm": {
       "removed": 8.442063486,
       "added": 10.485389285
      },
      "viasMoved": {
       "removed": 1,
       "added": 1
      },
      "rerouted": true
     },
     {
      "name": "+5V",
      "length": {
       "a": 978.737813446,
       "b": 978.738106305,
       "delta": 0.000292858,
       "perLayer": {
        "F.Cu": {
         "a": 644.903436933,
         "b": 644.903729791,
         "delta": 0.000292858
        }
       }
      },
      "width": {
       "min": {
        "a": 0.2,
        "b": 0.2
       },
       "max": {
        "a": 1.6,
        "b": 1.6
       },
       "perLayer": {}
      },
      "copperArea": {
       "a": 50.093272852,
       "b": 50.093272852,
       "delta": 0,
       "perLayer": {},
       "note": "pour (region) area only"
      },
      "vias": {
       "a": 16,
       "b": 16,
       "delta": 0,
       "drills": {
        "a": {
         "0.3": 10,
         "0.8": 6
        },
        "b": {
         "0.3": 10,
         "0.8": 6
        }
       },
       "drillDelta": {}
      },
      "pads": {
       "a": 93,
       "b": 93,
       "added": [],
       "removed": []
      },
      "reroutedLengthMm": {
       "removed": 6.812999722,
       "added": 6.800656227
      },
      "viasMoved": {
       "removed": 0,
       "added": 0
      },
      "rerouted": true
     },
     {
      "name": "GND",
      "length": {
       "a": 2371.390207287,
       "b": 2369.994273074,
       "delta": -1.395934213,
       "perLayer": {
        "F.Cu": {
         "a": 1450.035435006,
         "b": 1448.639500793,
         "delta": -1.395934213
        }
       }
      },
      "width": {
       "min": {
        "a": 0.2,
        "b": 0.2
       },
       "max": {
        "a": 1.6,
        "b": 1.6
       },
       "perLayer": {}
      },
      "copperArea": {
       "a": 29310.954046795,
       "b": 29311.950141932,
       "delta": 0.996095137,
       "perLayer": {
        "F.Cu": {
         "a": 13730.542214012,
         "b": 13730.956165536,
         "delta": 0.413951525
        },
        "B.Cu": {
         "a": 15580.411832783,
         "b": 15580.993976396,
         "delta": 0.582143613
        }
       },
       "note": "pour (region) area only"
      },
      "vias": {
       "a": 1455,
       "b": 1457,
       "delta": 2,
       "drills": {
        "a": {
         "0.3": 1441,
         "0.8": 14
        },
        "b": {
         "0.3": 1443,
         "0.8": 14
        }
       },
       "drillDelta": {
        "0.3": {
         "a": 1441,
         "b": 1443
        }
       }
      },
      "pads": {
       "a": 262,
       "b": 262,
       "added": [
        "C108.2",
        "C109.2"
       ],
       "removed": [
        "R6.1",
        "R8.1"
       ]
      },
      "reroutedLengthMm": {
       "removed": 26.156732316,
       "added": 24.988129377
      },
      "viasMoved": {
       "removed": 5,
       "added": 7
      },
      "rerouted": true
     }
    ]
   },
   "outline": {
    "changed": false,
    "loops": {
     "a": 8,
     "b": 8
    },
    "bbox": {
     "a": [
      91.1125,
      93.792,
      353.6125,
      189.04025
     ],
     "b": [
      91.1125,
      93.792,
      353.6125,
      189.04025
     ]
    },
    "size": {
     "a": [
      262.5,
      95.24825
     ],
     "b": [
      262.5,
      95.24825
     ]
    },
    "perimeterMm": {
     "a": 567.876702307,
     "b": 567.876702307,
     "delta": 0
    },
    "areaMm2": {
     "a": 10128.883844019,
     "b": 10128.883844019,
     "delta": 0
    },
    "changedLengthMm": {
     "removed": 0,
     "added": 0
    }
   },
   "stackup": {
    "changed": false,
    "added": [],
    "removed": [],
    "modified": [],
    "reordered": false,
    "thickness": null
   },
   "warnings": []
  },
  "bomDiff": {
   "summary": {
    "added": 1,
    "removed": 1,
    "qtyChanged": 1,
    "valueChanged": 1,
    "footprintChanged": 0,
    "mpnChanged": 0,
    "dnpToggled": 0,
    "categoryChanged": 0,
    "total": 4,
    "unchanged": 291
   },
   "added": [
    {
     "kind": "added",
     "category": "SCH",
     "key": "vf:10u 16v|cp_eia-3216-18_kemet-a",
     "part": {
      "value": "10u 16V",
      "footprint": "Capacitor_Tantalum_SMD:CP_EIA-3216-18_Kemet-A"
     },
     "qtyTo": 2,
     "refs": [
      "C108",
      "C109"
     ]
    }
   ],
   "removed": [
    {
     "kind": "removed",
     "category": "SCH",
     "key": "vf:0|r_0603_1608metric",
     "part": {
      "value": "0",
      "footprint": "Resistor_SMD:R_0603_1608Metric"
     },
     "qtyFrom": 2,
     "refs": [
      "R6",
      "R8"
     ]
    }
   ],
   "qtyChanged": [
    {
     "kind": "qty-changed",
     "category": "SCH",
     "key": "vf:47u 10v|c_1206_3216metric",
     "part": {
      "value": "47u 10V",
      "footprint": "Capacitor_SMD:C_1206_3216Metric"
     },
     "qtyFrom": 7,
     "qtyTo": 6,
     "refsAdded": [],
     "refsRemoved": [
      "C16"
     ],
     "refs": [
      "C8",
      "C28",
      "C30",
      "C84",
      "C101",
      "C102"
     ]
    }
   ],
   "valueChanged": [
    {
     "kind": "value-changed",
     "category": "SCH",
     "key": "vf:ams1117-3.3|sot-223-3_tabpin2",
     "part": {
      "value": "AMS1117-3.3",
      "footprint": "Package_TO_SOT_SMD:SOT-223-3_TabPin2"
     },
     "from": "TLV1117LV33",
     "to": "AMS1117-3.3",
     "refs": [
      "U3"
     ]
    }
   ],
   "footprintChanged": [],
   "mpnChanged": [],
   "dnpToggled": [],
   "categoryChanged": [],
   "byCategory": {
    "SCH": {
     "added": 1,
     "removed": 1,
     "qtyChanged": 1,
     "valueChanged": 1
    },
    "PCB": {},
    "BOARD_FEATURE": {}
   }
  },
  "impacts": [
   {
    "id": "13043db1b8b558cb",
    "kind": "bom",
    "ref": "C108",
    "refs": [
     "C108",
     "C109"
    ],
    "category": "SCH",
    "metric": "qty",
    "before": 0,
    "after": 2,
    "delta": 2,
    "severity": "info",
    "why": "SCH line 10u 16V CP_EIA-3216-18_Kemet-A: C108, C109 added (qty 0 -> 2).",
    "causes": [
     "bomDiff.added[C108]",
     "bomDiff.added[C109]"
    ],
    "assumptionDependent": false
   },
   {
    "id": "951999fd89b2cd47",
    "kind": "bom",
    "ref": "C16",
    "category": "SCH",
    "metric": "qty",
    "before": 7,
    "after": 6,
    "delta": -1,
    "severity": "info",
    "why": "SCH line 47u 10V C_1206_3216Metric: C16 qty changed (qty 7 -> 6).",
    "causes": [
     "bomDiff.qtyChanged[C16]"
    ],
    "assumptionDependent": false
   },
   {
    "id": "1ab144e51b2c95b8",
    "kind": "bom",
    "ref": "R6",
    "refs": [
     "R6",
     "R8"
    ],
    "category": "SCH",
    "metric": "qty",
    "before": 2,
    "after": 0,
    "delta": -2,
    "severity": "info",
    "why": "SCH line 0 R_0603_1608Metric: R6, R8 removed (qty 2 -> 0).",
    "causes": [
     "bomDiff.removed[R6]",
     "bomDiff.removed[R8]"
    ],
    "assumptionDependent": false
   },
   {
    "id": "a9c6ad56218ab244",
    "kind": "bom",
    "ref": "U3",
    "category": "SCH",
    "metric": "value",
    "before": "TLV1117LV33",
    "after": "AMS1117-3.3",
    "delta": null,
    "severity": "info",
    "why": "SCH line AMS1117-3.3 SOT-223-3_TabPin2: U3 value changed (TLV1117LV33 -> AMS1117-3.3).",
    "causes": [
     "bomDiff.valueChanged[U3]"
    ],
    "assumptionDependent": false
   },
   {
    "id": "80a645448fb1589d",
    "kind": "impedance",
    "net": "Net-(C16-Pad2)",
    "layer": "F.Cu",
    "metric": "z0Ohm",
    "before": 65.99,
    "after": null,
    "delta": null,
    "severity": "info",
    "why": "Net-(C16-Pad2): net removed; C16 removed; C16 removed from the 47u 10V line (qty 7 -> 6); +4 more - Z0 on F.Cu gone (was 65.99 ohm).",
    "causes": [
     "layoutDiff.components.removed[C16]",
     "layoutDiff.components.removed[R6]",
     "layoutDiff.components.removed[R8]",
     "layoutDiff.nets.removed[Net-(C16-Pad2)]"
    ],
    "assumptionDependent": true
   }
  ],
  "summary": {
   "counts": {
    "high": 0,
    "medium": 0,
    "low": 0,
    "info": 5
   },
   "headline": "5 informational change(s), none against a limit; first: SCH line 10u 16V CP_EIA-3216-18_Kemet-A: C108, C109 added (qty 0 -> 2).",
   "markdown": "**5 informational change(s), none against a limit; first: SCH line 10u 16V CP_EIA-3216-18_Kemet-A: C108, C109 added (qty 0 -> 2).** Layout: components: 2 added, 3 removed, 1 moved, 1 with a new value; nets: 1 removed, 3 rerouted. BOM: 1 line(s) added, 1 removed, 1 changed quantity, 1 changed value. Re-analysed on both revisions, for the changed nets and parts only: impedance, cert. Every electrical change is informational (improved, or no limit to judge against). Not run for missing inputs: cert.creepage, returnPath (see refused). Rows marked assumptionDependent rest on ledgered typical values."
  },
  "analysed": {
   "ran": [
    "impedance",
    "cert"
   ],
   "nets": [
    "+3V3",
    "+5V",
    "GND",
    "Net-(C16-Pad2)"
   ],
   "rails": []
  },
  "assumptions": {
   "before": [
    {
     "source": "default",
     "analysis": "impedance",
     "key": "mask.er",
     "value": 3.8,
     "citation": "LPI solder mask epsilon_r 3.8 (NativeCAD default)",
     "verified": false,
     "affects": [
      "outer-layer traces"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "fab",
     "value": "jlcpcb",
     "citation": "fab profile jlcpcb (NativeCAD default)",
     "verified": true,
     "affects": []
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipc6012.drillPositionTolMm",
     "value": 0.075,
     "unit": "mm",
     "citation": "NativeCAD default (typical standard-technology rigid fab; no fab publishes it)",
     "verified": false,
     "affects": [
      "ipc6012"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipc6012.innerRegistrationTolMm",
     "value": 0.075,
     "unit": "mm",
     "citation": "NativeCAD default (typical standard-technology rigid fab; no fab publishes it)",
     "verified": false,
     "affects": [
      "ipc6012"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipc6012.outerRegistrationTolMm",
     "value": 0.05,
     "unit": "mm",
     "citation": "NativeCAD default (typical standard-technology rigid fab; no fab publishes it)",
     "verified": false,
     "affects": [
      "ipc6012"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipcClass",
     "value": "2",
     "citation": "IPC-6012 Class 2 (dedicated service) - the general commercial default",
     "verified": true,
     "affects": []
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "motC",
     "value": 105,
     "citation": "requested MOT 105 C (FR-4 laminates' common UL RTI)",
     "verified": false,
     "affects": [],
     "unit": "C"
    },
    {
     "source": "default",
     "analysis": "returnPath",
     "key": "erEff",
     "value": 4,
     "citation": "effective epsilon_r 4 for the stitching distance (NativeCAD default)",
     "verified": false,
     "affects": []
    },
    {
     "source": "derived",
     "analysis": "returnPath",
     "key": "planes",
     "value": [],
     "citation": "inner layer with >= 30 % pour cover of one net (outer: >= 80 % and no other net's traces); voids = holes >= 2 mm^2 in that net's pours, as bounding rectangles",
     "affects": [
      "every finding"
     ]
    },
    {
     "source": "default",
     "analysis": "returnPath",
     "key": "riseTimeNs",
     "value": 1,
     "citation": "edge rise time 1 ns, f_knee = 0.35 / t_r (Johnson & Graham)",
     "verified": true,
     "affects": [],
     "unit": "ns"
    }
   ],
   "after": [
    {
     "source": "default",
     "analysis": "impedance",
     "key": "mask.er",
     "value": 3.8,
     "citation": "LPI solder mask epsilon_r 3.8 (NativeCAD default)",
     "verified": false,
     "affects": [
      "outer-layer traces"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "fab",
     "value": "jlcpcb",
     "citation": "fab profile jlcpcb (NativeCAD default)",
     "verified": true,
     "affects": []
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipc6012.drillPositionTolMm",
     "value": 0.075,
     "unit": "mm",
     "citation": "NativeCAD default (typical standard-technology rigid fab; no fab publishes it)",
     "verified": false,
     "affects": [
      "ipc6012"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipc6012.innerRegistrationTolMm",
     "value": 0.075,
     "unit": "mm",
     "citation": "NativeCAD default (typical standard-technology rigid fab; no fab publishes it)",
     "verified": false,
     "affects": [
      "ipc6012"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipc6012.outerRegistrationTolMm",
     "value": 0.05,
     "unit": "mm",
     "citation": "NativeCAD default (typical standard-technology rigid fab; no fab publishes it)",
     "verified": false,
     "affects": [
      "ipc6012"
     ]
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "ipcClass",
     "value": "2",
     "citation": "IPC-6012 Class 2 (dedicated service) - the general commercial default",
     "verified": true,
     "affects": []
    },
    {
     "source": "default",
     "analysis": "cert",
     "key": "motC",
     "value": 105,
     "citation": "requested MOT 105 C (FR-4 laminates' common UL RTI)",
     "verified": false,
     "affects": [],
     "unit": "C"
    },
    {
     "source": "default",
     "analysis": "returnPath",
     "key": "erEff",
     "value": 4,
     "citation": "effective epsilon_r 4 for the stitching distance (NativeCAD default)",
     "verified": false,
     "affects": []
    },
    {
     "source": "derived",
     "analysis": "returnPath",
     "key": "planes",
     "value": [],
     "citation": "inner layer with >= 30 % pour cover of one net (outer: >= 80 % and no other net's traces); voids = holes >= 2 mm^2 in that net's pours, as bounding rectangles",
     "affects": [
      "every finding"
     ]
    },
    {
     "source": "default",
     "analysis": "returnPath",
     "key": "riseTimeNs",
     "value": 1,
     "citation": "edge rise time 1 ns, f_knee = 0.35 / t_r (Johnson & Graham)",
     "verified": true,
     "affects": [],
     "unit": "ns"
    }
   ]
  },
  "refused": {
   "before": [
    {
     "analysis": "cert.creepage",
     "reasonCode": "pcb_analysis_needs_input",
     "needs": [
      "cert.pairs[].a",
      "cert.pairs[].b",
      "cert.pairs[].workingVrms"
     ],
     "remedy": "creepage needs the net pairs and the working voltage between them; UL 796 and IPC-6012 ran without them",
     "requested": false
    },
    {
     "analysis": "returnPath",
     "reasonCode": "pcb_analysis_needs_input",
     "needs": [
      "a reference plane (a poured copper layer)"
     ],
     "remedy": "no layer of this board is a plane, so there is no return path to check",
     "requested": false
    }
   ],
   "after": [
    {
     "analysis": "cert.creepage",
     "reasonCode": "pcb_analysis_needs_input",
     "needs": [
      "cert.pairs[].a",
      "cert.pairs[].b",
      "cert.pairs[].workingVrms"
     ],
     "remedy": "creepage needs the net pairs and the working voltage between them; UL 796 and IPC-6012 ran without them",
     "requested": false
    },
    {
     "analysis": "returnPath",
     "reasonCode": "pcb_analysis_needs_input",
     "needs": [
      "a reference plane (a poured copper layer)"
     ],
     "remedy": "no layer of this board is a plane, so there is no return path to check",
     "requested": false
    }
   ]
  }
 }
}