main
Ray pin 1: carry the footprint's marker into the .lbr, the viewer and page.json (silk-marker, drawn, top-left) 948b6f6
{
 "schema": "adom.pads/1",
 "slug": "tx4221",
 "footprint": "SOIC-8_3.9x4.9mm_P1.27mm",
 "generated_from": {
  "footprint": "SOIC-8_3.9x4.9mm_P1.27mm@sha256:074ecb2092b24fa4",
  "pins": "page.json:component.pins",
  "overrides": null
 },
 "pin1": {
  "pad": "1",
  "at": [
   -2.475,
   -1.905
  ],
  "corner": "top-left",
  "source": "silk-marker",
  "derived_from": "SOIC-8_3.9x4.9mm_P1.27mm@sha256:074ecb2092b24fa4"
 },
 "pad_count": 8,
 "symbol_pins": [
  "1",
  "2",
  "3",
  "4",
  "5",
  "6",
  "7",
  "8"
 ],
 "paste_apertures": 0,
 "issues": [],
 "pads": [
  {
   "pad": "1",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    -2.475,
    -1.905
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "1",
   "name": "DRV",
   "type": "output",
   "description": "Gate drive output for the external power MOSFET. Rise/fall time ~50 ns into 500 pF; absolute maximum 8 V.",
   "is_pin1": true,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "2",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    -2.475,
    -0.635
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "2",
   "name": "VDD",
   "type": "power_in",
   "description": "Chip supply input. Operating range 5-40 V (absolute max 45 V). UVLO threshold ~4.8 V; operating current ~2.5 mA at 200 kHz.",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "3",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    -2.475,
    0.635
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "3",
   "name": "EN",
   "type": "input",
   "description": "Chip enable, active high. VIH >= 3.2 V, VIL <= 0.8 V. Absolute max 45 V. Pulling EN low puts the chip in standby (~75 uA).",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "4",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    -2.475,
    1.905
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "4",
   "name": "ROSC",
   "type": "input",
   "description": "External resistor to GND sets the switching frequency: Fs = 4.83e7 / (ROSC + 1.08e5) Hz. With ROSC tied directly to GND the internal frequency defaults to ~450 kHz; typical values 100-330 kOhm (150 kHz at 330 kOhm).",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "5",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    2.475,
    1.905
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "5",
   "name": "FB",
   "type": "input",
   "description": "Output voltage feedback pin. Internal reference V_FB = 1.000 V (975-1025 mV). Vout = (R1+R2)/R1 * V_FB. Absolute max 6.5 V.",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "6",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    2.475,
    0.635
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "6",
   "name": "NC",
   "type": "unconnected",
   "description": "No connection; leave floating (悬空).",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "7",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    2.475,
    -0.635
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "7",
   "name": "GND",
   "type": "power_in",
   "description": "Device ground reference.",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  },
  {
   "pad": "8",
   "kind": "smd",
   "shape": "roundrect",
   "at": [
    2.475,
    -1.905
   ],
   "rot": 0.0,
   "size": [
    1.95,
    0.6
   ],
   "layers": [
    "F.Cu",
    "F.Mask",
    "F.Paste"
   ],
   "thermal": false,
   "pin": "8",
   "name": "VCS",
   "type": "input",
   "description": "MOSFET switch current-limit sense input. Over-current threshold typ. 250 mV (240-260 mV). Peak inductor current IPK <= 0.25 / R_CS. Absolute max 6.5 V.",
   "is_pin1": false,
   "source": {
    "geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
    "meaning": "page.json:component.pins",
    "correspondence": "kicad: symbol pin number == pad name"
   }
  }
 ]
}