Key Selection Information
| Selection Parameter | Confirmed Information |
|---|---|
| Channels | 2 bidirectional I²C/SMBus lines |
| Bus Speed | Up to 1 MHz stated |
| A-Side Supply | 1.65 V to 3.6 V |
| B-Side Supply | 2.3 V to 5.5 V; VCCA ≤ VCCB |
| Pull-Ups | Internal 10-kΩ pull-up resistors on SDA/SCL pins |
| Isolation | Ports high impedance if OE low or either supply at 0 V |
| Sequencing | No required power-supply sequencing |
| Exact Package / Packing | VSSOP (DCU), 8 pins; 3000-piece large reel; −40°C to +85°C |
Product Overview
TCA9406DCUR is an active dual-supply I²C translator whose defining system feature is internal pull-ups plus power-supply isolation. Unlike passive LSF/PCA pass translators, it explicitly uses VCCA and VCCB supply rails and places both ports high impedance when a supply disappears.
Internal 10-kΩ pull-ups reduce component count but may not be strong enough for every 1-MHz/high-capacitance bus. External bus design still needs to satisfy rise-time limits instead of assuming the internal resistors guarantee Fast-Mode Plus timing.
No supply sequencing requirement simplifies independently switched domains. The OE pin can also force isolation during hot-plug or fault recovery.
For related devices, see HKEQGOO’s Translators, Level Shifters category.
Technical Specifications
| Parameter | Verified Information |
|---|---|
| Manufacturer | Texas Instruments |
| Exact MPN | TCA9406DCUR |
| Channels | 2 bidirectional I²C/SMBus lines |
| Bus Speed | Up to 1 MHz stated |
| A-Side Supply | 1.65 V to 3.6 V |
| B-Side Supply | 2.3 V to 5.5 V; VCCA ≤ VCCB |
| Pull-Ups | Internal 10-kΩ pull-up resistors on SDA/SCL pins |
| Isolation | Ports high impedance if OE low or either supply at 0 V |
| Sequencing | No required power-supply sequencing |
| Exact Package / Packing | VSSOP (DCU), 8 pins; 3000-piece large reel; −40°C to +85°C |
| Manufacturer Status | Active / Production |
| Part Marking | F9 / NF9R / NZ family markings per TI addendum |
Functional Highlights
VCC isolation reduces back-power paths
If either side loses its supply, both ports become high impedance rather than allowing an I²C pull-up to feed an unpowered domain.
Internal pull-ups reduce simple-board BOM
For low-capacitance buses, the integrated resistors may be sufficient and remove four external components.
Design Considerations
- Calculate 10-kΩ pull-up rise time at the real bus capacitance; add/adjust external pull-ups if needed.
- Keep VCCA ≤ VCCB as specified.
- Use OE deliberately during hot-plug or domain reset if isolation timing matters.
Product Status and Exact Order Code
Texas Instruments/source evidence identifies TCA9406DCUR as Active / Production; VSSOP (DCU), 8 pins; 3000-piece large tape and reel; −40°C to +85°C.
Related Engineering Resources
Quality & Verification Support
Third-party inspection or testing can be arranged according to customer requirements. Testing fees are borne by the buyer. Additional verification requirements can be discussed before shipment. After an order is placed, physical product, label, packaging, and Date Code photos may be provided where appropriate.
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