Pololu Isolated USB-to-I²C Adapter with Isolated Power

This USB-to-I²C adapter enables a PC or other USB host to act as the controller on an I²C bus, reading and writing data from I²C target devices connected to the bus. It supports clock stretching and I²C clock speeds in excess of 1 MHz. The adapter features complete galvanic isolation between the USB and I²C sides, which prevents unexpected current flow between the two sides and protects the computer and its USB ports from destructive voltages on the I²C bus. This version delivers isolated power to the I²C side at 5V or 3.3V (selectable by an integrated switch with the state latched at start-up).