PCA9306 Level Shifter Molecule

{
  "schema_version": 1,
  "type": "component",
  "slug": "pca9306-level-shifter",
  "title": "PCA9306 Level Shifter Molecule",
  "brief": "Bidirectional 2-channel I2C/SMBus voltage-level translator molecule (TI PCA9306DCUR) — 1.8 V <-> 3.3 V, no one-shot ACK contention, 24x16 mm 4-pin Adom workcell molecule with 8 medium machine contacts",
  "version": "2.0.0",
  "tags": [],
  "license": "MIT",
  "discovery_triggers": [
    "PCA9306",
    "level shifter",
    "I2C level translator",
    "1.8V to 3.3V I2C",
    "bidirectional I2C",
    "voltage translator",
    "TXS0108E replacement",
    "TXS0108 alternative",
    "I2C ACK NACK",
    "one-shot accelerator",
    "BHI360 level shifter",
    "PCA9306DCUR",
    "VSSOP-8",
    "castellated breakout",
    "Adom molecule level shifter"
  ],
  "discovery_pitch": "PCA9306 level shifter molecule — 1.8 V to 3.3 V bidirectional I2C, drop-in fix for TXS0108E one-shot ACK contention, JLC-ready Gerbers and BOM included.",
  "sample_prompts": [
    {
      "label": "I2C 1.8V to 3.3V",
      "prompt": "Show me a 1.8V to 3.3V I2C level shifter molecule"
    },
    {
      "label": "PCA9306 breakout",
      "prompt": "Open the PCA9306 level shifter molecule"
    },
    {
      "label": "Replace TXS0108E",
      "prompt": "What molecule replaces a TXS0108E without the one-shot ACK contention?"
    },
    {
      "label": "Order from JLC",
      "prompt": "I want to order the PCA9306 level shifter molecule from JLC"
    },
    {
      "label": "Show the 3D viewer",
      "prompt": "Open the live 3D viewer for the PCA9306 level shifter"
    }
  ],
  "component": {
    "mpn": "PCA9306 Level Shifter Molecule",
    "manufacturer": "",
    "package": "",
    "pin_count": null,
    "category": "molecule",
    "subcategory": "",
    "body_size": null,
    "parts": {},
    "distributor_links": {}
  },
  "readme": "# PCA9306 Level Shifter Molecule — Plan\n\n## Brief\nDrop-in I²C / SMBus voltage-level translator molecule for Adom workcells. Bridges a 1.8 V bus to a 3.3 V (or up to 5 V) bus with no direction pin and **no one-shot accelerator contention** — the canonical replacement for the TXS0108E on the Bosch sensortec arm board, where the TXS family's one-shot rising-edge accelerator fights I²C slave open-drain ACK pull-down and produces address-NACK at probe time.\n\n## Decisions\n- **Tool:** adom-tsci / tscircuit (canonical Adom path).\n- **Size:** `24x16` — 4-pin molecule. Wider than tall so 4 + 4 perimeter contacts fit comfortably.\n- **Pin grid:** medium machine pins (4 corner pins + 4 edge contacts per long side).\n- **IC:** TI PCA9306DCUR in VSSOP-8 (DCU package). LCSC C58662 (JLC extended).\n- **EN handling:** internally tied to VREF2 via a 10 kΩ pull-up (always-enabled by default). Cut the R5 trace if external EN control is needed later.\n- **Pull-ups:** 4.7 kΩ on SDA1, SCL1 → VREF1; 4.7 kΩ on SDA2, SCL2 → VREF2. UNI-ROYAL 0402 (LCSC C25900 — JLC basic).\n- **Decoupling:** one 100 nF 0402 X7R on each VREF rail, placed within 1 mm of the IC pin. Samsung CL05B104KO5NNNC (LCSC C1525 — JLC basic).\n- **Top silkscreen:** \"PCA9306\", function tag, pin labels on every contact.\n- **Bottom silkscreen:** part name, \"1.8V <-> 3.3V I2C\", version + author + date.\n\n## Components\n| Ref | Value | Package | MPN | LCSC |\n|-----|-------|---------|-----|------|\n| U1  | PCA9306DCUR | VSSOP-8 | PCA9306DCUR | C58662 |\n| C1, C2 | 100 nF 25 V X7R | 0402 | CL05B104KO5NNNC | C1525 |\n| R1..R4 | 4.7 kΩ 1 % | 0402 | 0402WGF4701TCE | C25900 |\n| R5 | 10 kΩ 1 % | 0402 | 0402WGF1002TCE | C25744 |\n\n## Workcell interface (8 medium machine contacts)\n| Pin | Net   | Side  | Notes |\n|-----|-------|-------|-------|\n| MC_VREF1 | VREF1 | left (LV) | 1.71–1.89 V supply |\n| MC_SDA1  | SDA1  | left | 1.8 V SDA, 4.7 kΩ to VREF1 |\n| MC_SCL1  | SCL1  | left | 1.8 V SCL, 4.7 kΩ to VREF1 |\n| MC_GND1  | GND   | left | shared ground |\n| MC_VREF2 | VREF2 | right (HV) | 3.3 V supply |\n| MC_SDA2  | SDA2  | right | 3.3 V SDA, 4.7 kΩ to VREF2 |\n| MC_SCL2  | SCL2  | right | 3.3 V SCL, 4.7 kΩ to VREF2 |\n| MC_GND2  | GND   | right | shared ground |\n\n## Don'ts\n- No BGA / 0201.\n- No external EN pin.\n- Only one JLC extended part (U1 itself); everything else basic-tier.\n\n## Publish\n```bash\ncd ~/project/adom-tsci-projects/pca9306-level-shifter\nbun install\nbunx tsci build lib/index.tsx --glbs --svgs --3d-png --pcb-png\nadom-tsci start .\nadom-tsci export-wiki --slug pca9306-level-shifter --page-type molecules\n```\n",
  "author": {
    "name": "Kyle Bergstedt",
    "email": "[email protected]"
  },
  "visibility": {
    "public": true
  },
  "hero": null,
  "metadata": {},
  "created_at": "2026-05-28T05:30:50.078Z",
  "updated_at": "2026-05-28T05:30:50.078Z",
  "org": "adom"
}