25LC256

{
  "schema_version": 1,
  "type": "component",
  "slug": "25lc256",
  "title": "25LC256",
  "brief": "Microchip 256 Kbit (32 KB) SPI EEPROM, SOIC-8. Byte/page write, 1M+ cycles, write protect. The SPI 24LC256. Datasheet-verified.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "memory",
    "eeprom",
    "spi",
    "non-volatile",
    "soic-8",
    "microchip"
  ],
  "component": {
    "mpn": "25LC256",
    "manufacturer": "Microchip Technology",
    "package": "SOIC-8",
    "pin_count": 8,
    "category": "Memory",
    "subcategory": "256 Kbit SPI EEPROM",
    "datasheet": "https://ww1.microchip.com/downloads/aemDocuments/documents/MPD/ProductDocuments/DataSheets/25AA256-25LC256-256K-SPI-Bus-Serial-EEPROM-20001822H.pdf",
    "parts": {
      "symbol": "25lc256.kicad_sym",
      "footprint": "25lc256.kicad_mod",
      "model_3d": "25lc256-etched.glb",
      "model_3d_plain": "25lc256.glb",
      "lbr": "25lc256.lbr",
      "model_3d_step": "25lc256-etched.step",
      "model_3d_step_plain": "25lc256.step"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "CS",
        "type": "input",
        "description": "Chip Select input (active-low, overbar CS). Drive low to select the device and initiate an SPI instruction; drive high to deselect and place SO in high-impedance. Requires TCSS setup (≥50 ns @ Vcc≥4.5 V) before the first SCK edge."
      },
      {
        "number": "2",
        "name": "SO",
        "type": "output",
        "description": "Serial Data Output (MISO). Shifts data out on the falling edge of SCK, MSB first. High-impedance when CS is high or HOLD is low. Drive strength: VOH = Vcc-0.5 V @ IOH = -400 µA."
      },
      {
        "number": "3",
        "name": "WP",
        "type": "input",
        "description": "Write-Protect input (active-low, overbar WP). When low and the WPEN bit in the status register is set, prevents writes to the status register (hardware write-protect). Tie high (or leave floating with pull-up) for normal operation."
      },
      {
        "number": "4",
        "name": "VSS",
        "type": "power_in",
        "description": "Ground reference for all supply, logic, and I/O signals. Connect to system 0 V."
      },
      {
        "number": "5",
        "name": "SI",
        "type": "input",
        "description": "Serial Data Input (MOSI). Command bytes, addresses, and write data are shifted in on the rising edge of SCK, MSB first. Data setup Tsu ≥ 10 ns @ Vcc ≥ 4.5 V."
      },
      {
        "number": "6",
        "name": "SCK",
        "type": "input",
        "description": "Serial Clock Input. Provides the clock for all serial data transfers on SI/SO. Maximum 10 MHz @ Vcc ≥ 4.5 V (5 MHz @ 2.5-4.5 V, 3 MHz @ 1.8-2.5 V for 25AA256). Supports SPI Mode 0,0 and Mode 1,1."
      },
      {
        "number": "7",
        "name": "HOLD",
        "type": "input",
        "description": "Hold input (active-low, overbar HOLD). Drive low to pause the current SPI transaction while CS remains asserted; SO goes high-impedance and SI/SCK transitions are ignored. Drive high to resume. Tie high if not used."
      },
      {
        "number": "8",
        "name": "VCC",
        "type": "power_in",
        "description": "Supply voltage input. 2.5-5.5 V for 25LC256 (1.8-5.5 V for 25AA256). Absolute max 6.5 V. Typical operating current 2.5 mA read / 0.6 mA write @ 5.5 V; standby 0.1 µA typ. Decouple with 0.1 µF close to the pin."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://ww1.microchip.com/downloads/aemDocuments/documents/MPD/ProductDocuments/DataSheets/25AA256-25LC256-256K-SPI-Bus-Serial-EEPROM-20001822H.pdf",
        "pages": 31,
        "sha256": "b25667250a0ee8d3",
        "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": "25lc256.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.0,
          4.9,
          1.75
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "07f46cff378d30e6c27dfd5a03092c795323f86d91c71fc7e743f4f418dc553a",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "25lc256-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.0,
          4.9,
          1.75
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "75f7b2c706ea10a584f89402d9f858a34898d4584b2dbdb8a70bd8eb7f50d342",
        "checked": "2026-11-03",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Type": "Serial EEPROM (non-volatile)",
      "Density": "256 Kbit (32 KB)",
      "Interface": "SPI (up to 10 MHz)",
      "Write": "byte or 64-byte page",
      "Endurance": "1,000,000+ cycles",
      "Retention": ">200 years",
      "Protection": "WP pin + block-protect bits",
      "Supply voltage": "1.8-5.5 V",
      "Package": "SOIC-8"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "25lc256",
    "spi eeprom",
    "serial eeprom",
    "32kb eeprom",
    "nonvolatile memory"
  ],
  "discovery_pitch": "25LC256 256 Kbit SPI EEPROM (SOIC-8) with datasheet-verified pinout, KiCad symbol/footprint/3D, and full provenance.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "25lc256.kicad_sym",
    "25lc256.kicad_mod",
    "25lc256.glb",
    "25lc256.lbr",
    "docs/hero.png",
    "docs/25lc256-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "25lc256-etched.step"
  ]
}