SPI isolator for field-bus and sensor links
The ADUM4154ARIZ is a 4-channel SPI digital isolator from Analog Devices' iCoupler and SPIsolator families, built with magnetic coupling for unidirectional signal transfer across a 5000Vrms isolation barrier.
The 5000Vrms isolation rating qualifies this part for reinforced insulation in mains-connected equipment — think industrial drives with 480VAC bus voltages or medical devices needing patient protection. The 25kV/µs common-mode transient immunity means it won't glitch during motor PWM switching or relay contact bounce, which is the kind of noise that corrupts SPI frames on non-isolated links. The 2.5ns typical rise/fall times keep signal edges clean at 2Mbps without excessive ringing, and the 2ns max pulse-width distortion means the clock-to-data skew stays tight enough for SPI mode 0 and mode 3 timing.
Supply and logic-level flexibility
With a supply range of 3V to 5.5V on both sides, this isolator works with 3.3V MCUs and 5V peripherals on the same chip — no external level translator needed. The 3/1 input-side/side-2 split (three channels from side 1 to side 2, one reverse) maps naturally to SPI: SCLK, MOSI, and CS from the controller, and MISO back from the peripheral. The unidirectional channel type means each channel is fixed-direction, so verify your SPI bus direction matches the pinout before layout.
Package and production status
Housed in a 20-SOIC wide-body (7.50mm width) package, surface-mount, supplied in tube. No official second source is listed, but the iCoupler family includes multiple SPI isolators with similar pinouts — check the channel count and direction before substituting.