# TCA4311ADR

**Texas Instruments** · Signal Buffers, Repeaters, Splitters · SOIC-8

TCA4311ADR from Texas Instruments, in a SOIC-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | EN | input | Active-high chip enable: when EN is low the device enters a low-current mode (<1 µA) and isolates the two sides, and EN should be held high at VCC for normal operation, with VIH of 2 V minimum and VIL of 0.8 V maximum. |
| 2 | SCLOUT | bidirectional | Serial clock output that connects to the SCL bus on the card side and is buffered from SCLIN, with open-drain I/O and a pull-up resistor required on this side. |
| 3 | SCLIN | bidirectional | Serial clock input that connects to the SCL bus on the backplane side and is buffered to SCLOUT, with open-drain I/O and a pull-up resistor required on this side. |
| 4 | GND | power_in | Supply ground for the device. |
| 5 | READY | output | Open-drain connection flag and rise-time accelerator control that is low while EN is low or start-up is incomplete, goes high when the backplane and card sides are connected, and needs a 10-kΩ pull-up resistor to VCC. |
| 6 | SDAIN | bidirectional | Serial data input that connects to the SDA bus on the backplane side and is buffered to SDAOUT, with open-drain I/O and a pull-up resistor required on this side. |
| 7 | SDAOUT | bidirectional | Serial data output that connects to the SDA bus on the card side and is buffered from SDAIN, with open-drain I/O and a pull-up resistor required on this side. |
| 8 | VCC | power_in | Supply voltage from the backplane, specified from 2.7 V to 5.5 V, with a bypass capacitor of at least 0.01 µF placed close to the pin. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-8 |
| Category | Interface |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `TCA4311ADR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `tca4311adr-etched.step` / `tca4311adr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tca4311adr.step` / `tca4311adr.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/tca4311a.pdf) (30 pp, sha256 `d01087e7243208db`, retrieved 2026-10-08, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/tca4311adr-datasheet.pdf)