The Adafruit TCA4307 Hot-Swap I2C Buffer protects your main I2C bus from glitches caused by hot-plugging STEMMA QT / Qwiic peripherals. I2C wasn't designed for hot-swapping, and plugging or unplugging at the wrong moment can hang the bus. This buffer sits between your controller and peripherals, isolating the bus during connect/disconnect events.

Connect the IN side to your controller (Arduino, Raspberry Pi, Feather, etc.) and any I2C sensors to the OUT side. The chip handles up to 400 kHz I2C and includes automatic stuck bus recovery — if SDA or SCL is held low for ~40 ms, it disconnects and sends up to 16 clock pulses to reset the stuck device.

Key Features

• TCA4307 I2C Buffer – Hot-swap protection for I2C peripherals
• Stuck Bus Recovery – Automatic disconnect and 16-pulse reset after ~40 ms timeout
• Up to 400 kHz – Standard and Fast mode I2C support
• 2.3–5.5V Logic – Wide voltage range for controller and peripherals
• EN Pin – Manually disconnect IN and OUT sides
• READY Pin – Indicates when peripheral is safely connected and ready for communication
• STEMMA QT / Qwiic – Solderless I2C connectors on both sides

Ideal For

• STEMMA QT / Qwiic projects with frequent sensor swapping
• Protecting I2C buses from hot-plug glitches
• Recovering from stuck I2C bus conditions
• Prototyping setups with multiple interchangeable sensors

Package Contents

• 1× TCA4307 hot-swap I2C buffer breakout (assembled and tested)