The ADUM1440ARQZ is a 4-channel, unidirectional digital isolator from the iCoupler family, built around magnetic coupling technology. It's a general-purpose part sized for isolating SPI, UART, or slow-to-moderate-speed control signals where 2 Mbps is enough headroom — think PLC I/O, sensor interfaces, or isolated power-supply feedback loops. The 2500 Vrms isolation rating covers basic/reinforced isolation in industrial and medical equipment without the overhead of a 5 kV part.
4/0 channel direction — all inputs on one side
All four channels run from Side 1 to Side 2 (inputs on Side 1, outputs on Side 2). That matters when you're isolating a unidirectional bus like a SPI master-to-slave link — you get four forward channels without wasting a channel on a reverse path. If your design needs bidirectional isolation (e.g., I²C), you'll need a part with mixed-direction channels or external direction control. The unidirectional architecture keeps propagation delay tight at 180 ns max (both tpHL and tpLH), with pulse-width distortion held to 8 ns max — clean enough for most control and data-acquisition links at 2 Mbps.
25 kV/µs CMTI — why it matters for motor drives and inverters
Common-mode transient immunity is rated at 25 kV/µs minimum. In a motor-drive or inverter environment, fast voltage swings on the high-side ground (from IGBT switching) can couple through the isolation barrier and corrupt data. A CMTI floor of 25 kV/µs means this part holds data integrity through those transients without bit errors. Rise and fall times are 2 ns typical, which keeps edge-rate distortion low and reduces radiated emissions when the layout is tight.
Package and footprint — 16-QSOP
The ADUM1440ARQZ comes in a 16-lead QSOP (body 3.90 mm wide, 0.154" pitch), with a surface-mount footprint that matches standard 16-pin SSOP/QSOP land patterns. No exposed pad, so thermal dissipation is through the leads — fine for the low quiescent draw of this part, but worth noting if ambient temperature pushes toward 125°C with all channels active.
Lifecycle and compliance
No AEC-Q100 qualification is listed, so for automotive-grade requirements you'd look at the ADUM1440W variant (if available) or a separate qualification lot.