CJ431K

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  "type": "component",
  "slug": "cj431k",
  "title": "CJ431K",
  "brief": "Changjing Voltage Reference, SOT-23. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.2.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
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    "pmic",
    "cj431k"
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  "component": {
    "mpn": "CJ431K",
    "manufacturer": "Changjing",
    "package": "SOT-23",
    "pin_count": 3,
    "category": "PMIC",
    "subcategory": "Voltage Reference",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/743503eba66546a89b989cb2a804230f.pdf",
    "parts": {
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      "footprint": "cj431k.kicad_mod",
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      "model_3d_plain": "cj431k.glb",
      "model_3d_step": "cj431k-etched.step",
      "model_3d_step_plain": "cj431k.step",
      "lbr": "cj431k.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "REF",
        "type": "input",
        "description": "Reference input. Internally compared to the 2.5V bandgap reference (Vref = 2.470-2.520 V typ). Drives the shunt element on when REF exceeds Vref. Reference input current is ~1.5 µA typ (4 µA max)."
      },
      {
        "number": "2",
        "name": "CATHODE",
        "type": "passive",
        "description": "Cathode (K) of the shunt regulator. Sinks 1-100 mA in the on state; VKA max 37 V, IKA range −100 to +150 mA. Off-state cathode current is 0.5 µA max at VKA = 40 V, Vref = 0."
      },
      {
        "number": "3",
        "name": "ANODE",
        "type": "passive",
        "description": "Anode (A) of the shunt regulator, connected to the low-side / ground return of the shunt current path."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
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        "url": "https://datasheet.lcsc.com/datasheet/pdf/743503eba66546a89b989cb2a804230f.pdf",
        "pages": 6,
        "sha256": "f02682f21931ad72",
        "source_tier": "lcsc"
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      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 3,
        "described": 3,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "pin1": {
      "pad": "1",
      "at": [
        -0.9375,
        -0.95
      ],
      "corner": "top-left",
      "source": "silk-marker",
      "derived_from": "SOT-23@sha256:0d88c86c1b6d8c1a",
      "mark": "drawn"
    },
    "models_3d": [
      {
        "file": "cj431k.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          2.5,
          3,
          1.2
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "dd5d1711204e1d8d26cd11490923bd84340820baa69538c385a4300ec2539bc0",
        "checked": "2026-10-07",
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        "checked": "2026-10-07",
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    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "Changjing",
      "Package": "SOT-23",
      "Category": "PMIC",
      "Pins": "3"
    },
    "characteristics": {
      "version": 1,
      "source": "datasheet",
      "datasheet_sha256": "f02682f21931ad72",
      "rows": [
        {
          "name": "Reference Input Voltage",
          "symbol": "Vref",
          "kind": "electrical",
          "unit": "V",
          "min": 2.47,
          "typ": null,
          "max": 2.52,
          "conditions": "VKA=VREF, IKA=10mA",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Deviation of Reference Input Voltage Over Temperature",
          "symbol": "△Vref/T",
          "kind": "temperature_coefficient",
          "unit": "mV",
          "min": null,
          "typ": 4.5,
          "max": 17,
          "conditions": "VKA=VREF, IKA=10mA, Tmin≤Ta≤Tmax (TMIN=-25℃, TMAX=+125℃)",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Ratio of Change in Reference Input Voltage to Change in Cathode Voltage",
          "symbol": "△Vref/△VKA",
          "kind": "voltage_coefficient",
          "unit": "mV/V",
          "min": null,
          "typ": -1,
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          "source_page": 2,
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        },
        {
          "name": "Ratio of Change in Reference Input Voltage to Change in Cathode Voltage",
          "symbol": "△Vref/△VKA",
          "kind": "voltage_coefficient",
          "unit": "mV/V",
          "min": null,
          "typ": -0.5,
          "max": -2,
          "conditions": "IKA=10mA, △VKA=36V~10V",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Reference Input Current",
          "symbol": "lref",
          "kind": "electrical",
          "unit": "μA",
          "min": null,
          "typ": 1.5,
          "max": 4,
          "conditions": "IKA=10mA, R1=10kΩ, R2=∞",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Deviation of Reference Input Current Over Full Temperature Range",
          "symbol": "△lref/T",
          "kind": "temperature_coefficient",
          "unit": "μA",
          "min": null,
          "typ": 0.4,
          "max": 1.2,
          "conditions": "IKA=10mA, R1=10kΩ, R2=∞",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Minimum Cathode Current for Regulation",
          "symbol": "IKA(min)",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 0.45,
          "max": 1,
          "conditions": "VKA=VREF",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Off-state Cathode Current",
          "symbol": "IKA(OFF)",
          "kind": "electrical",
          "unit": "μA",
          "min": null,
          "typ": 0.05,
          "max": 0.5,
          "conditions": "VKA=40V, VREF=0",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Dynamic Impedance",
          "symbol": "ZKA",
          "kind": "electrical",
          "unit": "Ω",
          "min": null,
          "typ": 0.15,
          "max": 0.5,
          "conditions": "VKA=VREF, IKA=1 to 100mA, f≤1.0kHz",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Cathode Voltage",
          "symbol": "VKA",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 37,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Cathode Current Range (Continuous)",
          "symbol": "IKA",
          "kind": "absolute_maximum",
          "unit": "mA",
          "min": -100,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Reference Input Current Range",
          "symbol": "Iref",
          "kind": "absolute_maximum",
          "unit": "mA",
          "min": 0.05,
          "typ": null,
          "max": 10,
          "conditions": "",
          "source_page": 1,
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        },
        {
          "name": "Power Dissipation",
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          "unit": "mW",
          "min": null,
          "typ": null,
          "max": 300,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Operating Ambient Temperature Range",
          "symbol": "Topr",
          "kind": "absolute_maximum",
          "unit": "℃",
          "min": -25,
          "typ": null,
          "max": 125,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Storage Temperature Range",
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          "unit": "℃",
          "min": -65,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 1,
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        },
        {
          "name": "Operating Junction Temperature",
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          "min": null,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 1,
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        },
        {
          "name": "Thermal Resistance from Junction to Ambient",
          "symbol": "RθJA",
          "kind": "thermal",
          "unit": "℃/W",
          "min": null,
          "typ": 417,
          "max": null,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Equivalent Temperature Factor (whole temperature range)",
          "symbol": "",
          "kind": "temperature_coefficient",
          "unit": "ppm/℃",
          "min": null,
          "typ": 50,
          "max": null,
          "conditions": "Typical value over the whole temperature scope (features list)",
          "source_page": 1,
          "source": "datasheet"
        }
      ]
    }
  },
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  "discovery_pitch": "CJ431K (Changjing) component page with datasheet-verified CAD.",
  "author": {
    "name": "Ray"
  },
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  "variants": [
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      "mpn": "CJ431KK",
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  ],
  "updated_at": "2026-09-24T19:05:54.143Z"
}