Adafruit ISO1540 Bidirectional I2C Isolator

Sometimes you'll find yourself with an I2C bus controller on one side and an I2C bus device on the other, needing to keep them electrically separated. Whether dealing with Earth-grounded devices or a power monitoring setup, the Adafruit ISO1540 Bidirectional I2C Isolator offers full electrical isolation between two sides of an I2C bus.

Powered by the TI ISO1540 chip, this isolator is fully bidirectional, supports clock rates up to 1 MHz, accommodates clock-stretching, and operates with 3 to 5V DC power or logic on each side. It provides 2500 V-RMS isolation, ensuring separation in high-risk scenarios.

Its user-friendly design includes power, ground, clock, and data breakout pads for each side, along with matching STEMMA QT connectors. Unlike other QT boards, each side is electrically isolated, requiring separate power sources. Ensure the green LED is lit on both sides to confirm functionality before transmitting data over I2C.

The board comes with 10K pull-ups on each side from the I2C pins to the respective VCC. To facilitate rapid integration, the board is designed in the STEMMA QT form factor, compatible with SparkFun Qwiic connectors, allowing solderless connections or chaining with other sensors and accessories via compatible cables. Note that a QT Cable is not included, but available for purchase separately.