I²C bus isolator with magnetic coupling — what it does
The Analog Devices LTC4310CDD-1#PBF is a 2-channel unidirectional digital isolator designed specifically for I²C buses. It uses magnetic coupling to provide galvanic isolation between the primary and secondary sides of the I²C interface, while maintaining the 100 kHz standard-mode data rate. The part supports a supply range of 3V to 5.5V, so it can bridge a 3.3V controller to a 5V peripheral or vice versa without a separate level shifter.
20 kV/µs CMTI — where it matters
The minimum common-mode transient immunity of 20 kV/µs means this isolator can reject fast voltage transients between the two grounds — a typical requirement when the I²C bus crosses a motor-drive boundary, a power-supply isolation barrier, or any environment where ground potential shifts rapidly. The 1 ns typical rise and fall times keep the I²C signal edges clean at 100 kHz, but the fast edges also mean the layout needs care: keep the isolation barrier clear of noisy traces to avoid coupling transients across the package.
If the design needs -40°C to 85°C or wider, look at the industrial-temperature variants in the LTC4310 family.
Package and footprint — 10-DFN with exposed pad
The LTC4310CDD-1#PBF comes in a 10-WFDFN exposed pad package (3x3 mm body). The DFN package is MSL 1, so no bake is needed before reflow if the moisture barrier bag is intact. Surface-mount only; no through-hole option exists.