MCP23S17T-E/SS

{
  "slug": "mcp23s17t-e-ss",
  "version": "0.2.1",
  "type": "component",
  "description": "Microchip I/O Expanders, SSOP-28-208mil. Datasheet-verified pinout, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "interface",
    "mcp23s17t-e"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "mcp23s17t-e.kicad_sym",
    "mcp23s17t-e.kicad_mod",
    "mcp23s17t-e.glb",
    "mcp23s17t-e.step",
    "mcp23s17t-e-etched.step",
    "mcp23s17t-e.lbr",
    "docs/hero.png",
    "docs/mcp23s17t-e-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "pads.json",
    "mcp23s17t-e-etched.glb",
    "mcp23s17t-e-ss-hero.glb",
    "mcp23s17t-e-ss-hero.overlay.json"
  ],
  "component": {
    "mpn": "MCP23S17T-E/SS",
    "manufacturer": "Microchip",
    "package": "SSOP-28-208mil",
    "pin_count": 28,
    "category": "Interface",
    "subcategory": "I/O Expanders",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/4d3b1e9ec84b4ae2a51dedd9e4a0ee55.pdf",
    "parts": {
      "symbol": "mcp23s17t-e.kicad_sym",
      "footprint": "mcp23s17t-e.kicad_mod",
      "model_3d": "mcp23s17t-e-ss-hero.glb",
      "model_3d_plain": "mcp23s17t-e.glb",
      "model_3d_step": "mcp23s17t-e-etched.step",
      "model_3d_step_plain": "mcp23s17t-e.step",
      "lbr": "mcp23s17t-e.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "GPB0",
        "type": "bidirectional",
        "description": "PORTB bit 0. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "2",
        "name": "GPB1",
        "type": "bidirectional",
        "description": "PORTB bit 1. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "3",
        "name": "GPB2",
        "type": "bidirectional",
        "description": "PORTB bit 2. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "4",
        "name": "GPB3",
        "type": "bidirectional",
        "description": "PORTB bit 3. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "5",
        "name": "GPB4",
        "type": "bidirectional",
        "description": "PORTB bit 4. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "6",
        "name": "GPB5",
        "type": "bidirectional",
        "description": "PORTB bit 5. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "7",
        "name": "GPB6",
        "type": "bidirectional",
        "description": "PORTB bit 6. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "8",
        "name": "GPB7",
        "type": "bidirectional",
        "description": "PORTB bit 7. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "9",
        "name": "VDD",
        "type": "power_in",
        "description": "Positive supply voltage. Operating range 1.8 V to 5.5 V (industrial) or 4.5 V to 5.5 V (extended, -40 to +125°C). Bypass locally with 0.1 µF."
      },
      {
        "number": "10",
        "name": "VSS",
        "type": "power_in",
        "description": "Ground reference (0 V)."
      },
      {
        "number": "11",
        "name": "CS",
        "type": "input",
        "description": "SPI chip select, active low. Frames a SPI transaction on the MCP23S17."
      },
      {
        "number": "12",
        "name": "SCK",
        "type": "input",
        "description": "SPI serial clock input (up to 10 MHz)."
      },
      {
        "number": "13",
        "name": "SI",
        "type": "input",
        "description": "SPI serial data input (MOSI from host)."
      },
      {
        "number": "14",
        "name": "SO",
        "type": "output",
        "description": "SPI serial data output (MISO to host). Typically driven only during a read cycle."
      },
      {
        "number": "15",
        "name": "A0",
        "type": "input",
        "description": "Hardware address bit 0. Must be externally tied to VDD or VSS; combined with A1/A2 forms the SPI device address."
      },
      {
        "number": "16",
        "name": "A1",
        "type": "input",
        "description": "Hardware address bit 1. Must be externally tied to VDD or VSS."
      },
      {
        "number": "17",
        "name": "A2",
        "type": "input",
        "description": "Hardware address bit 2. Must be externally tied to VDD or VSS; up to 8 devices share the bus."
      },
      {
        "number": "18",
        "name": "RESET",
        "type": "input",
        "description": "Hardware reset, active low. Must be tied high (or driven high) for normal operation; asserting low returns all registers to POR defaults."
      },
      {
        "number": "19",
        "name": "INTB",
        "type": "output",
        "description": "Interrupt output for PORTB. Configurable as active-high, active-low, or open-drain (via IOCON register)."
      },
      {
        "number": "20",
        "name": "INTA",
        "type": "output",
        "description": "Interrupt output for PORTA. Configurable as active-high, active-low, or open-drain; can be mirrored with INTB."
      },
      {
        "number": "21",
        "name": "GPA0",
        "type": "bidirectional",
        "description": "PORTA bit 0. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "22",
        "name": "GPA1",
        "type": "bidirectional",
        "description": "PORTA bit 1. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "23",
        "name": "GPA2",
        "type": "bidirectional",
        "description": "PORTA bit 2. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "24",
        "name": "GPA3",
        "type": "bidirectional",
        "description": "PORTA bit 3. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "25",
        "name": "GPA4",
        "type": "bidirectional",
        "description": "PORTA bit 4. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "26",
        "name": "GPA5",
        "type": "bidirectional",
        "description": "PORTA bit 5. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "27",
        "name": "GPA6",
        "type": "bidirectional",
        "description": "PORTA bit 6. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      },
      {
        "number": "28",
        "name": "GPA7",
        "type": "bidirectional",
        "description": "PORTA bit 7. Bidirectional I/O pin with optional interrupt-on-change and internal weak pull-up."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://datasheet.lcsc.com/datasheet/pdf/4d3b1e9ec84b4ae2a51dedd9e4a0ee55.pdf",
        "pages": 48,
        "sha256": "0d23e5d2e71a68cd",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 28,
        "described": 28,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "pin1": {
      "pad": "1",
      "at": [
        -3.5,
        -4.225
      ],
      "corner": "top-left",
      "source": "silk-marker",
      "derived_from": "SSOP-28_5.3x10.2mm_P0.65mm@sha256:bbb0d0449b996c0a",
      "mark": "drawn"
    },
    "models_3d": [
      {
        "file": "mcp23s17t-e.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          7.8,
          10.2,
          2.1
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "7aa76979ae41da44bded1ed74115012868f2f3f5a757faf32bb9df4f92c1e313",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "mcp23s17t-e-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          7.8,
          10.2,
          2.1
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "16d2990980fd0c3c04508eea1ae59a2e83812600fd2d421d4a9028d0e967ac31",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ],
    "family": {
      "base": "MCP23S17T-E",
      "siblings": [
        "MCP23S17T-E/ML",
        "MCP23S17T-E/SO"
      ],
      "old_slug": "mcp23s17t-e",
      "note": "renamed from the cut-base slug to the part it was built from (slug collision split, 2026-11-11)"
    }
  },
  "title": "MCP23S17T-E/SS",
  "brief": "Microchip I/O Expanders, SSOP-28-208mil. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.",
  "metadata": {
    "specs": {
      "Manufacturer": "Microchip",
      "Package": "SSOP-28-208mil",
      "Category": "Interface",
      "Pins": "28"
    }
  },
  "discovery_triggers": [
    "mcp23s17t-e"
  ],
  "discovery_pitch": "MCP23S17T-E (Microchip) component page with datasheet-verified CAD.",
  "visibility": "public"
}