SI8421BB-D-IS

{
  "schema_version": 1,
  "type": "component",
  "slug": "si8421bb-d-is",
  "title": "SI8421BB-D-IS",
  "brief": "Skyworks Solutions Digital Isolators, SOIC-8. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "signal isolation devices",
    "si8421bb-d-is",
    "factory-2.0.0",
    "extractor-text"
  ],
  "component": {
    "mpn": "SI8421BB-D-IS",
    "manufacturer": "Skyworks Solutions",
    "package": "SOIC-8",
    "pin_count": 8,
    "category": "Signal Isolation Devices",
    "subcategory": "Digital Isolators",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/3d1a2b5105cb3f204bef3d127623df2c.pdf",
    "parts": {
      "symbol": "si8421bb-d-is.kicad_sym",
      "footprint": "si8421bb-d-is.kicad_mod",
      "model_3d": "si8421bb-d-is-hero.glb",
      "model_3d_plain": "si8421bb-d-is-etched.glb",
      "model_3d_step": "si8421bb-d-is-etched.step",
      "model_3d_step_plain": "si8421bb-d-is.step",
      "lbr": "si8421bb-d-is.lbr"
    },
    "distributor_links": {
      "lcsc": "C5899699",
      "digikey": "336-1756-5-ND",
      "mouser": "634-SI8421BB-D-IS"
    },
    "distributor_check": {
      "checked_at": "2026-10-23T12:03:10Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": "336-1756-5-ND",
        "status": "found",
        "lifecycle": "Not For New Designs"
      },
      "mouser": {
        "pn": "634-SI8421BB-D-IS",
        "status": "found",
        "lifecycle": "Not Recommended for New Designs"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "VDD1",
        "type": "power_in",
        "description": "Side 1 power supply, operating range 2.70 V to 5.5 V, with 0.1 µF and 1 µF bypass capacitors to GND1 recommended."
      },
      {
        "number": "2",
        "name": "A1",
        "type": "input",
        "description": "Side 1 digital input or output; on the Si8421 it is the single VDD1-side input channel, passing data to B1."
      },
      {
        "number": "3",
        "name": "A2",
        "type": "output",
        "description": "Side 1 digital input or output; on the Si8421 it is the reverse channel output carrying data from B2."
      },
      {
        "number": "4",
        "name": "GND1",
        "type": "power_in",
        "description": "Side 1 ground."
      },
      {
        "number": "5",
        "name": "GND2",
        "type": "power_in",
        "description": "Side 2 ground."
      },
      {
        "number": "6",
        "name": "B2",
        "type": "input",
        "description": "Side 2 digital input or output; on the Si8421 it is the VDD2-side input channel, passing data to A2."
      },
      {
        "number": "7",
        "name": "B1",
        "type": "output",
        "description": "Side 2 digital input or output; it is the output of the forward channel from A1."
      },
      {
        "number": "8",
        "name": "VDD2",
        "type": "power_in",
        "description": "Side 2 power supply, operating range 2.70 V to 5.5 V, with 0.1 µF and 1 µF bypass capacitors to GND2 recommended."
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.3",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins 0.3",
        "primary_model": "claude-sonnet-5-5",
        "primary_mode": "text",
        "consensus_model": "claude-sonnet-5-5",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [
          "extractor flagged: The pin table lists A1, A2, B1 and B2 only as 'Digital I/O' (input or output). I inferred the direct; The datasheet is marked 'Not Recommended for New Designs'. The Si8421BB-D-IS is a Revision D, 150 Mb"
        ],
        "pages_sent": 15,
        "cost_usd": 0.1415,
        "at": "2026-10-23T12:02:44"
      },
      "datasheet": {
        "url": "https://datasheet.lcsc.com/datasheet/pdf/3d1a2b5105cb3f204bef3d127623df2c.pdf",
        "pages": 30,
        "sha256": "1d36dd3ebae3afcd",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 8,
        "described": 8,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "si8421bb-d-is.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6,
          4.9,
          1.75
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "07f46cff378d30e6c27dfd5a03092c795323f86d91c71fc7e743f4f418dc553a",
        "checked": "2026-10-23",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "si8421bb-d-is-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6,
          4.9,
          1.75
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "6e5c01babec7e9a51a0b00c6d6f23f50621756cee81a2a3607d62da7062c7df9",
        "checked": "2026-10-23",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "Skyworks Solutions",
      "Package": "SOIC-8",
      "Category": "Signal Isolation Devices",
      "Pins": "8"
    },
    "characteristics": {
      "version": 1,
      "source": "datasheet",
      "datasheet_sha256": "1d36dd3ebae3afcd0192e53d43cef5b47b8bbf7cb3525469c01efe9b238dc52c",
      "rows": [
        {
          "name": "Ambient Operating Temperature",
          "symbol": "TA",
          "kind": "recommended_operating",
          "unit": "°C",
          "min": -40,
          "typ": 25,
          "max": 125,
          "conditions": "150 Mbps, 15 pF, 5 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Supply Voltage VDD1",
          "symbol": "VDD1",
          "kind": "recommended_operating",
          "unit": "V",
          "min": 2.7,
          "typ": null,
          "max": 5.5,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Supply Voltage VDD2",
          "symbol": "VDD2",
          "kind": "recommended_operating",
          "unit": "V",
          "min": 2.7,
          "typ": null,
          "max": 5.5,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Storage Temperature",
          "symbol": "TSTG",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": -65,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Operating Temperature",
          "symbol": "TA",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": -40,
          "typ": null,
          "max": 125,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Supply Voltage (Revision D)",
          "symbol": "VDD1, VDD2",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": -0.5,
          "typ": null,
          "max": 6,
          "conditions": "Revision D",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Input Voltage",
          "symbol": "VI",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": -0.5,
          "typ": null,
          "max": null,
          "conditions": "max = VDD + 0.5 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Output Voltage",
          "symbol": "VO",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": -0.5,
          "typ": null,
          "max": null,
          "conditions": "max = VDD + 0.5 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Output Current Drive Channel",
          "symbol": "IO",
          "kind": "absolute_maximum",
          "unit": "mA",
          "min": null,
          "typ": null,
          "max": 10,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Lead Solder Temperature (10 s)",
          "symbol": "",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": null,
          "typ": null,
          "max": 260,
          "conditions": "10 s",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Maximum Isolation Voltage (1 s)",
          "symbol": "",
          "kind": "absolute_maximum",
          "unit": "VRMS",
          "min": null,
          "typ": null,
          "max": 3600,
          "conditions": "1 s",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "High Level Input Voltage",
          "symbol": "VIH",
          "kind": "electrical",
          "unit": "V",
          "min": 2,
          "typ": null,
          "max": null,
          "conditions": "VDD1 = VDD2 = 5 V ±10%, TA = –40 to 125 °C",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "Low Level Input Voltage",
          "symbol": "VIL",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 0.8,
          "conditions": "VDD1 = VDD2 = 5 V ±10%, TA = –40 to 125 °C",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "High Level Output Voltage",
          "symbol": "VOH",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": 4.8,
          "max": null,
          "conditions": "Ioh = –4 mA; min printed as VDD1,VDD2 – 0.4",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "Low Level Output Voltage",
          "symbol": "VOL",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": 0.2,
          "max": 0.4,
          "conditions": "Iol = 4 mA",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "Input Leakage Current",
          "symbol": "IL",
          "kind": "electrical",
          "unit": "µA",
          "min": -10,
          "typ": null,
          "max": 10,
          "conditions": "",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "Output Impedance",
          "symbol": "ZO",
          "kind": "electrical",
          "unit": "Ω",
          "min": null,
          "typ": 85,
          "max": null,
          "conditions": "nominal ±40% (note 1)",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "DC Supply Current VDD1, inputs 0",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 1.3,
          "max": 2,
          "conditions": "Si8421Ax, Bx; All inputs 0 DC",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "DC Supply Current VDD2, inputs 0",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 1.3,
          "max": 2,
          "conditions": "Si8421Ax, Bx; All inputs 0 DC",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "DC Supply Current VDD1, inputs 1",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 2.3,
          "max": 3.5,
          "conditions": "Si8421Ax, Bx; All inputs 1 DC",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "DC Supply Current VDD2, inputs 1",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 2.3,
          "max": 3.5,
          "conditions": "Si8421Ax, Bx; All inputs 1 DC",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "1 Mbps Supply Current VDD1",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 1.9,
          "max": 2.9,
          "conditions": "Si8421Ax, Bx; All inputs = 500 kHz square wave, CI = 15 pF on all outputs",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "1 Mbps Supply Current VDD2",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 1.9,
          "max": 2.9,
          "conditions": "Si8421Ax, Bx; All inputs = 500 kHz square wave, CI = 15 pF on all outputs",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "10 Mbps Supply Current VDD1",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 2.2,
          "max": 3.3,
          "conditions": "Si8421Bx; All inputs = 5 MHz square wave, CI = 15 pF on all outputs",
          "source_page": 6,
          "source": "datasheet"
        },
        {
          "name": "10 Mbps Supply Current VDD2",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 2.2,
          "max": 3.3,
          "conditions": "Si8421Bx; All inputs = 5 MHz square wave, CI = 15 pF on all outputs",
          "source_page": 6,
          "source": "datasheet"
        },
        {
          "name": "100 Mbps Supply Current VDD1 (5 V)",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 5.8,
          "max": 7.3,
          "conditions": "Si8421Bx; All inputs = 50 MHz square wave, CI = 15 pF on all outputs; VDD = 5 V ±10%",
          "source_page": 6,
          "source": "datasheet"
        },
        {
          "name": "100 Mbps Supply Current VDD2 (5 V)",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 5.8,
          "max": 7.3,
          "conditions": "Si8421Bx; All inputs = 50 MHz square wave, CI = 15 pF on all outputs; VDD = 5 V ±10%",
          "source_page": 6,
          "source": "datasheet"
        },
        {
          "name": "Maximum Data Rate",
          "symbol": "",
          "kind": "timing",
          "unit": "Mbps",
          "min": 0,
          "typ": null,
          "max": 150,
          "conditions": "Si8421Bx",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Minimum Pulse Width",
          "symbol": "",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": null,
          "max": 6,
          "conditions": "Si8421Bx",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Propagation Delay",
          "symbol": "tPHL, tPLH",
          "kind": "timing",
          "unit": "ns",
          "min": 3,
          "typ": 6,
          "max": 9.5,
          "conditions": "See Figure 1",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Pulse Width Distortion |tPLH - tPHL|",
          "symbol": "PWD",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 1.5,
          "max": 2.5,
          "conditions": "See Figure 1",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Propagation Delay Skew",
          "symbol": "tPSK(P-P)",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 2,
          "max": 3,
          "conditions": "",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Channel-Channel Skew",
          "symbol": "tPSK",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 0.5,
          "max": 1.8,
          "conditions": "",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Output Rise Time (5 V)",
          "symbol": "tr",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 3.8,
          "max": 5,
          "conditions": "CL = 15 pF",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Output Fall Time (5 V)",
          "symbol": "tf",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 2.8,
          "max": 3.7,
          "conditions": "CL = 15 pF",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Common Mode Transient Immunity",
          "symbol": "CMTI",
          "kind": "electrical",
          "unit": "kV/µs",
          "min": null,
          "typ": 25,
          "max": null,
          "conditions": "VI = VDD or 0 V",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "Start-up Time",
          "symbol": "tSU",
          "kind": "timing",
          "unit": "µs",
          "min": null,
          "typ": 15,
          "max": 40,
          "conditions": "",
          "source_page": 7,
          "source": "datasheet"
        },
        {
          "name": "100 Mbps Supply Current VDD1 (3.3 V)",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 4.4,
          "max": 5.5,
          "conditions": "Si8421Bx; All inputs = 50 MHz square wave, CI = 15 pF on all outputs; VDD = 3.3 V ±10%",
          "source_page": 9,
          "source": "datasheet"
        },
        {
          "name": "100 Mbps Supply Current VDD2 (3.3 V)",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 4.4,
          "max": 5.5,
          "conditions": "Si8421Bx; All inputs = 50 MHz square wave, CI = 15 pF on all outputs; VDD = 3.3 V ±10%",
          "source_page": 9,
          "source": "datasheet"
        },
        {
          "name": "Output Rise Time (3.3 V)",
          "symbol": "tr",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 4.3,
          "max": 6.1,
          "conditions": "CL = 15 pF; VDD = 3.3 V ±10%",
          "source_page": 10,
          "source": "datasheet"
        },
        {
          "name": "Output Fall Time (3.3 V)",
          "symbol": "tf",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 3,
          "max": 4.3,
          "conditions": "CL = 15 pF; VDD = 3.3 V ±10%",
          "source_page": 10,
          "source": "datasheet"
        },
        {
          "name": "100 Mbps Supply Current VDD1 (2.70 V)",
          "symbol": "IDD1",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 3.7,
          "max": 4.6,
          "conditions": "Si8421Bx; All inputs = 50 MHz square wave, CI = 15 pF on all outputs; VDD = 2.70 V",
          "source_page": 12,
          "source": "datasheet"
        },
        {
          "name": "100 Mbps Supply Current VDD2 (2.70 V)",
          "symbol": "IDD2",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 3.7,
          "max": 4.6,
          "conditions": "Si8421Bx; All inputs = 50 MHz square wave, CI = 15 pF on all outputs; VDD = 2.70 V",
          "source_page": 12,
          "source": "datasheet"
        },
        {
          "name": "Output Rise Time (2.70 V)",
          "symbol": "tr",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 4.8,
          "max": 6.5,
          "conditions": "CL = 15 pF; VDD = 2.70 V",
          "source_page": 13,
          "source": "datasheet"
        },
        {
          "name": "Output Fall Time (2.70 V)",
          "symbol": "tf",
          "kind": "timing",
          "unit": "ns",
          "min": null,
          "typ": 3.2,
          "max": 4.6,
          "conditions": "CL = 15 pF; VDD = 2.70 V",
          "source_page": 13,
          "source": "datasheet"
        },
        {
          "name": "Junction-to-Air Thermal Resistance",
          "symbol": "θJA",
          "kind": "thermal",
          "unit": "°C/W",
          "min": null,
          "typ": 140,
          "max": null,
          "conditions": "",
          "source_page": 16,
          "source": "datasheet"
        },
        {
          "name": "Case Temperature (safety limit)",
          "symbol": "TS",
          "kind": "thermal",
          "unit": "°C",
          "min": null,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 15,
          "source": "datasheet"
        },
        {
          "name": "Safety input, output, or supply current",
          "symbol": "IS",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": null,
          "max": 160,
          "conditions": "θJA = 140 °C/W, VI = 5.5 V, TJ = 150 °C, TA = 25 °C",
          "source_page": 15,
          "source": "datasheet"
        },
        {
          "name": "Device Power Dissipation",
          "symbol": "PD",
          "kind": "electrical",
          "unit": "mW",
          "min": null,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 15,
          "source": "datasheet"
        }
      ]
    }
  },
  "variants": [],
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "si8421bb-d-is"
  ],
  "discovery_pitch": "SI8421BB-D-IS (Skyworks Solutions) component page: datasheet pinout, KiCad symbol, footprint and 3D.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "si8421bb-d-is.kicad_sym",
    "si8421bb-d-is.kicad_mod",
    "si8421bb-d-is.glb",
    "si8421bb-d-is.step",
    "si8421bb-d-is.lbr",
    "docs/hero.png",
    "docs/si8421bb-d-is-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "si8421bb-d-is-hero.glb",
    "si8421bb-d-is-hero.overlay.json",
    "si8421bb-d-is-etched.glb"
  ],
  "visibility": {
    "public": true
  }
}