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. The 25 kV/µs common-mode transient immunity is the spec that matters when the isolator straddles a noisy power stage — a motor-drive inverter, a switching power supply, or a battery charger. 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.
Lifecycle and sourcing
It is an Analog Devices original, not a second-source clone. No last-time-buy or phase-out notice is in effect.