I²C bus isolator — 2500Vrms galvanic isolation for mixed-voltage domains
The ADUM1251ARZ-RL7: It provides 2500Vrms galvanic isolation between two I²C bus segments, handling bidirectional SDA and SCL lines with one unidirectional channel for an additional signal. The 1Mbps data rate covers standard and fast-mode I²C operation up to 400kHz plus headroom for clock stretching. Supply range from 3V to 5.5V lets it bridge a 3.3V controller side to a 5V sensor side without a separate level shifter.
Why the 25kV/µs CMTI and 2500Vrms matter for your BOM
Common-mode transient immunity of 25kV/µs minimum means this isolator won't glitch the I²C bus when a motor-drive IGBT switches at several kV/µs — a real failure mode in inverter-fed systems. The 2500Vrms isolation rating satisfies basic reinforced insulation requirements for many industrial and medical applications. Pulse width distortion is specified at 145ns max for the bidirectional channels and 85ns for the unidirectional one, so the SCL/SDA timing budget stays intact even with the isolation barrier in the path.