UC3842-TD

{
  "schema_version": 1,
  "type": "component",
  "slug": "uc3842-td",
  "title": "UC3842-TD",
  "brief": "TDSEMIC DC-DC Converters, SOP-8. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.2.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "pmic",
    "uc3842-td"
  ],
  "component": {
    "mpn": "UC3842-TD",
    "manufacturer": "TDSEMIC",
    "package": "SOP-8",
    "pin_count": 8,
    "category": "PMIC",
    "subcategory": "DC-DC Converters",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/020157c85102df19b71d3e50321bb05b.pdf",
    "parts": {
      "symbol": "uc3842-td.kicad_sym",
      "footprint": "uc3842-td.kicad_mod",
      "model_3d": "uc3842-td-etched.glb",
      "model_3d_plain": "uc3842-td.glb",
      "model_3d_step": "uc3842-td-etched.step",
      "model_3d_step_plain": "uc3842-td.step",
      "lbr": "uc3842-td.lbr"
    },
    "distributor_links": {
      "lcsc": "C42422130"
    },
    "pins": [
      {
        "number": "1",
        "name": "COMP",
        "type": "output",
        "description": "Error amplifier output. Used for external loop compensation via an RC network between COMP and VFB (pin 2)."
      },
      {
        "number": "2",
        "name": "VFB",
        "type": "input",
        "description": "Inverting input of the internal error amplifier. Normally connected via a resistor divider from the regulated switching-supply output; compared against the internal 2.5 V reference on the non-inverting input."
      },
      {
        "number": "3",
        "name": "ISENSE",
        "type": "input",
        "description": "Current-sense input. Voltage proportional to primary-side switch current (across a sense resistor Rs) is applied here. PWM latch resets when this input exceeds the internal 1 V threshold, providing cycle-by-cycle current limiting."
      },
      {
        "number": "4",
        "name": "RT/CT",
        "type": "passive",
        "description": "Oscillator timing pin. Connect RT from VREF (pin 8) to this pin and CT from this pin to GND to set the oscillator frequency and maximum duty cycle. Maximum operating frequency 500 kHz."
      },
      {
        "number": "5",
        "name": "GND",
        "type": "power_in",
        "description": "Signal and power ground return for the IC."
      },
      {
        "number": "6",
        "name": "OUTPUT",
        "type": "output",
        "description": "Totem-pole gate driver output for the external power MOSFET. Capable of sourcing/sinking peak currents up to 1 A. Internally clamped by a 22 V zener."
      },
      {
        "number": "7",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply for the control IC. UVLO turn-on at ~16 V (typ) and turn-off at ~10 V (typ) with ~29 V internal zener clamp. Absolute maximum 30 V. Startup current < 0.5 mA (Ist ≤ 0.3 mA at Vi=14 V)."
      },
      {
        "number": "8",
        "name": "VREF",
        "type": "power_out",
        "description": "5 V (±2%) trimmed bandgap reference output. Sources up to ~30 mA (Isc typ -100 mA). Typically feeds the oscillator timing resistor RT to charge CT on pin 4."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://datasheet.lcsc.com/datasheet/pdf/020157c85102df19b71d3e50321bb05b.pdf",
        "pages": 9,
        "sha256": "350281e75156b241",
        "source_tier": "lcsc"
      },
      "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"
    },
    "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",
      "mark": "drawn"
    },
    "models_3d": [
      {
        "file": "uc3842-td.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": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "uc3842-td-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": "31258b17c82fe9064d1a673d8064ffdb5d5bda0177997391f2b2ea294420a3a4",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "TDSEMIC",
      "Package": "SOP-8",
      "Category": "PMIC",
      "Pins": "8"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "uc3842-td"
  ],
  "discovery_pitch": "UC3842-TD (TDSEMIC) component page with datasheet-verified CAD.",
  "author": {
    "name": "Ray"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "uc3842-td.kicad_sym",
    "uc3842-td.kicad_mod",
    "uc3842-td.glb",
    "uc3842-td.step",
    "uc3842-td-etched.step",
    "uc3842-td.lbr",
    "docs/hero.png",
    "docs/uc3842-td-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html"
  ],
  "visibility": {
    "public": true
  },
  "variants": [
    {
      "mpn": "UC3842-TDM/TR",
      "kind": "packaging"
    },
    {
      "mpn": "UC3842-TDN",
      "kind": "packaging"
    }
  ],
  "updated_at": "2026-09-25T13:29:28.741Z"
}