Two-channel unidirectional isolation for automotive signal chains
The ADUM1281WARZ: It provides 3000Vrms galvanic isolation between two independent supply domains, with one channel per side (one input on side 1, one input on side 2).
1Mbps data rate with 50ns propagation delay
Data rate is rated at 1Mbps, with a maximum propagation delay of 50ns (tPLH / tPHL) and pulse-width distortion held to 10ns. Rise and fall times are symmetrical at 2.5ns typical. This timing budget suits isolated SPI, UART, and general-purpose GPIO isolation at moderate speeds — the 1Mbps ceiling is a comfortable fit for CAN transceiver isolation (typically 500kbps to 1Mbps) and for breaking ground loops in sensor readout lines without introducing excessive skew. The 25kV/µs minimum common-mode transient immunity (CMTI) means the isolator holds its output state through fast voltage spikes on the isolation barrier, which is critical in motor-drive and inverter environments where switching transients exceed 10kV/µs.
3V to 5.5V supply — single-rail operation
The part does not include an integrated isolated DC-DC converter (isolated power: No), so each side requires its own local supply rail — a clean 3.3V or 5V from the system regulator, with the usual 0.1µF decoupling caps placed close to the supply pins.