I²C bus isolator for noisy environments
The Maxim Integrated MAX14933ASE+ is a 2-channel bidirectional digital isolator purpose-built for I²C bus isolation. It uses capacitive coupling to achieve 2750Vrms galvanic isolation between the two sides, with a common-mode transient immunity of 25kV/µs (typ) — enough to keep the data link alive in motor-drive, inverter, and industrial power-stage environments where fast switching edges couple noise onto the bus. Each of the two channels is bidirectional, matching the open-drain, bidirectional nature of the I²C clock and data lines. The supply range spans 2.25V to 5.5V on both sides, so it works with 3.3V and 5V I²C domains without a level shifter.
Package and footprint
Housed in a 16-pin SOIC package with a 3.90mm body width (0.154"), surface-mount only. The narrow SOIC footprint is common for I²C isolators, so the layout should transfer cleanly from a standard 16-SOIC land pattern. No isolated power is generated on-chip — both sides need their own supply rail.