The ADUM3154BRSZ-RL7 is a dedicated SPI bus digital isolator from Analog Devices' iCoupler® SPIsolator™ family, using magnetic coupling to provide galvanic isolation for serial peripheral interface links. It delivers a 34 Mbps data rate across four unidirectional channels arranged as three on the primary side and one on the secondary side, which matches the typical SPI signal set (SCLK, MOSI, MISO, and a chip-select or interrupt line). The 3750 Vrms isolation rating covers reinforced isolation requirements for industrial fieldbus, motor drives, and medical equipment where the safety barrier must hold off transient overvoltages. Propagation delay is 14 ns max in both directions, and pulse-width distortion stays under 2 ns, so the clock-to-data skew budget remains tight enough for 34 Mbps SPI without needing to slow the bus.
Channel mapping and timing — the SPI-specific layout
The 3/1 input-side-to-output-side split (three inputs on side 1, one input on side 2) is intentional for SPI: the master-side clock, MOSI, and chip-select go through the three forward channels, while the MISO return path uses the single reverse channel. Rise and fall times are 2.5 ns typical, which keeps edge rates fast enough for 34 Mbps but not so aggressive that they cause excessive ringing on a well-terminated trace. Common-mode transient immunity is 25 kV/µs minimum, meaning the part holds its output state through fast voltage swings on the isolation barrier — relevant when the secondary side sits on a motor-drive high-voltage rail or a noisy inverter ground.
Package and temperature grade
Housed in a 20-SSOP package (5.30 mm body width), surface-mount only. No isolated power converter is integrated — the ADUM3154BRSZ-RL7 is a signal-only isolator; the secondary-side supply must come from an external isolated DC-DC or a separate rail.