component
PCA9306 Level Shifter Molecule
UnreviewedBidirectional 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
3D Model
Symbol & Footprint
Schematic
PCB Footprint
PCA9306 Level Shifter Molecule — Plan
Brief
Drop-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.
Decisions
- Tool: adom-tsci / tscircuit (canonical Adom path).
- Size:
24x16— 4-pin molecule. Wider than tall so 4 + 4 perimeter contacts fit comfortably. - Pin grid: medium machine pins (4 corner pins + 4 edge contacts per long side).
- IC: TI PCA9306DCUR in VSSOP-8 (DCU package). LCSC C58662 (JLC extended).
- 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.
- Pull-ups: 4.7 kΩ on SDA1, SCL1 → VREF1; 4.7 kΩ on SDA2, SCL2 → VREF2. UNI-ROYAL 0402 (LCSC C25900 — JLC basic).
- Decoupling: one 100 nF 0402 X7R on each VREF rail, placed within 1 mm of the IC pin. Samsung CL05B104KO5NNNC (LCSC C1525 — JLC basic).
- Top silkscreen: "PCA9306", function tag, pin labels on every contact.
- Bottom silkscreen: part name, "1.8V <-> 3.3V I2C", version + author + date.
Components
| Ref | Value | Package | MPN | LCSC |
|---|---|---|---|---|
| U1 | PCA9306DCUR | VSSOP-8 | PCA9306DCUR | C58662 |
| C1, C2 | 100 nF 25 V X7R | 0402 | CL05B104KO5NNNC | C1525 |
| R1..R4 | 4.7 kΩ 1 % | 0402 | 0402WGF4701TCE | C25900 |
| R5 | 10 kΩ 1 % | 0402 | 0402WGF1002TCE | C25744 |
Workcell interface (8 medium machine contacts)
| Pin | Net | Side | Notes |
|---|---|---|---|
| MC_VREF1 | VREF1 | left (LV) | 1.71–1.89 V supply |
| MC_SDA1 | SDA1 | left | 1.8 V SDA, 4.7 kΩ to VREF1 |
| MC_SCL1 | SCL1 | left | 1.8 V SCL, 4.7 kΩ to VREF1 |
| MC_GND1 | GND | left | shared ground |
| MC_VREF2 | VREF2 | right (HV) | 3.3 V supply |
| MC_SDA2 | SDA2 | right | 3.3 V SDA, 4.7 kΩ to VREF2 |
| MC_SCL2 | SCL2 | right | 3.3 V SCL, 4.7 kΩ to VREF2 |
| MC_GND2 | GND | right | shared ground |
Don'ts
- No BGA / 0201.
- No external EN pin.
- Only one JLC extended part (U1 itself); everything else basic-tier.
Publish
cd ~/project/adom-tsci-projects/pca9306-level-shifter
bun install
bunx tsci build lib/index.tsx --glbs --svgs --3d-png --pcb-png
adom-tsci start .
adom-tsci export-wiki --slug pca9306-level-shifter --page-type molecules
