Four channels, one direction scheme
The ADUM4401ARIZ is a 4-channel digital isolator from Analog Devices' iCoupler series, using magnetic coupling to pass signals across a 5000Vrms isolation barrier. It runs on a supply from 3V to 5.5V on both sides, making it a straight drop into 3.3V or 5V logic domains without a separate rail converter. The channel direction is fixed: three inputs on side 1, one input on side 2 — a 3/1 split that suits isolating a three-line bus (like SPI's SCK, MOSI, CS) on the primary side while the single return path (MISO) comes back from the isolated side.
1Mbps and 25kV/µs — what they mean on a motor drive
Data rate is capped at 1Mbps, so this part handles UART at 115200 baud, I2C at 400kHz, and SPI clock up to about 1MHz with margin. For faster serial links you'd step up to the 10Mbps or 100Mbps iCoupler variants. The 25kV/µs common-mode transient immunity is the spec that matters in an inverter or motor-drive environment: when the IGBT switches, the ground plane jumps, and a weak isolator lets that transient through as a data glitch. At 25kV/µs this part holds the line through the kind of noise that kills optocouplers without a separate bias circuit.
Industrial temperature, no isolated power
The part does not include an integrated DC-DC converter for isolated power; you supply Vdd1 and Vdd2 separately, each from its own side's rail. On a 24V industrial backplane, that usually means a small isolated brick or a separate isolated module for the secondary side.
Package and footprint
Housed in a 16-pin SOIC wide-body (0.295-inch / 7.50mm width), surface-mount. The wide-body SOIC gives better creepage distance for the 5000Vrms rating compared to the narrow SOIC-8. No exposed pad, so rework with a standard hot-air station is straightforward — no thermal pad to worry about, just the 16 gull-wing leads.