It is designed for SPI bus isolation in systems where the controller and peripheral are on separate ground domains — motor drives, industrial PLCs, medical patient-monitoring interfaces, and isolated sensor front-ends. The part provides three channels from side 1 to side 2 and one channel in the reverse direction, matching the typical SPI signal set (SCLK, MOSI, CS, MISO).
The 3750Vrms isolation voltage sets the safety barrier rating — sufficient for reinforced insulation in medical equipment per IEC 60601 and for basic insulation in 240VAC industrial systems. The 2Mbps data rate is the maximum SPI clock speed the isolator can sustain; for a 10 MHz SPI bus this part is too slow, but for typical configuration and sensor readout buses running at 1-2 MHz it fits cleanly. The 25kV/µs common-mode transient immunity is the key spec for motor-drive and inverter applications — it determines how well the isolator rejects switching noise from the power stage without corrupting the SPI frame. The 3V to 5.5V supply range allows operation on either 3.3V or 5V rails without a separate level shifter, simplifying the power tree. Propagation delay is 25ns max in both directions, with pulse-width distortion held to 2ns. These timing figures matter for SPI bus timing closure — the round-trip delay through the isolator plus the cable must still meet the peripheral's setup/hold window. Rise and fall times are 2.5ns typical, which keeps edge rates controlled enough to avoid excessive ringing on short PCB traces.
Package and rework considerations
The 20-SSOP package with 0.209 inch body width and 5.30mm height is a standard fine-pitch SOIC footprint. The part is surface-mount only, ships in tube, and is MSL 3 per the iCoupler family norm. If the moisture-barrier bag has been open past the floor-life window, bake at 125°C for 24 hours before reflow. The 20-SSOP lead pitch is 0.65mm — a standard fine-tip iron or hot-air station can hand-rework it without lifting pads, provided the board has adequate thermal relief on the ground pins.
Lifecycle and supply posture
For dual-sourcing resilience, the ADUM3154ARSZ is the standard SPIsolator variant — there is no direct pin-compatible second source from another manufacturer, but the iCoupler family includes other channel-count and data-rate options in the same 20-SSOP footprint if the design needs to trade off speed or directionality.