What this isolator does on your board
The ADUM1401CRWZ is a 4-channel, unidirectional digital isolator from Analog Devices' iCoupler series, built around magnetic coupling technology rather than the older optocoupler approach. It passes digital signals across a 2500Vrms isolation barrier at up to 90Mbps, with three channels driving from Side 1 to Side 2 and one channel going the reverse direction. The wide-body 16-SOIC package gives the creepage distance needed to maintain the isolation rating across the board.
90 Mbps and 2.5 ns edges — what they mean for signal integrity
The 90Mbps data rate with 2.5ns typical rise and fall times means this part can handle fast serial interfaces like SPI at 20-30 MHz clock rates with clean edges. Propagation delay is 32ns max in either direction, and pulse-width distortion is held to 2ns max — tight enough that duty-cycle-sensitive signals like PWM or Manchester-encoded data pass through without significant skew.
Supply voltage spans 2.7V to 5.5V on both sides, so you can run the isolated side at a different logic level than the controller side — 3.3V on one side and 5V on the other, for example — without a separate level shifter. No isolated power converter is built in; each side needs its own local supply rail.