SPI bus isolation with the right channel count
The ADUM3152ARSZ is a 7-channel, unidirectional digital isolator from Analog Devices' iCoupler and SPIsolator families, purpose-built for isolating SPI buses. Its 4/3 input-side/side-2 split maps directly to the four standard SPI signals (SCLK, MOSI, MISO, SS) plus three additional control or interrupt lines, so you don't waste channels or need a second device. The magnetic coupling technology provides 3750Vrms isolation, and the 2 Mbps data rate supports SPI clock speeds up to roughly 2 MHz — adequate for most sensor readouts, ADC conversions, and configuration registers in industrial and motor-drive applications.
3750Vrms and 25 kV/µs CMTI — what they mean on the board
The 3750Vrms isolation rating is the basic safety barrier for reinforced insulation in many industrial and medical designs. Fast voltage swings across the barrier can couple through a weaker isolator and corrupt the SPI data; the ADUM3152ARSZ's CMTI rating keeps the data path clean through those transients. The 25 ns max propagation delay (both directions) is tight enough for back-to-back SPI transactions without adding a clock-stretching penalty.
Supply range and dual-voltage operation
The part operates from 3V to 5.5V on each side independently, so you can run the controller side at 3.3V and the isolated peripheral side at 5V — or any combination within that range. This is common in systems where the MCU is 3.3V but the isolated ADC or sensor runs on a 5V rail. No external isolated DC-DC is required for the isolator itself (the Isolated Power spec is No), but the load-side circuitry may still need its own isolated supply.
Temperature range and deployment environments
The rise/fall time of 2.5 ns typical keeps signal edges sharp enough for 2 Mbps SPI without excessive ringing, provided the layout keeps trace lengths short.
It is an Analog Devices original, not a second-source clone. No last-time-buy or phase-out notice is in effect.