Four-channel forward isolator for 2.5 V / 3.3 V logic domains
The ADUM1445ARQZ is a four-channel, unidirectional digital isolator from Analog Devices' iCoupler series, built around magnetic coupling technology. It provides 2500 Vrms isolation between two supply domains, with all four channels oriented from Side 1 to Side 2 (4/0 input-side/side-2 ratio). Typical applications include SPI bus isolation, UART isolation, GPIO isolation in industrial sensors, PLC I/O modules, motor drives, and isolated power-supply feedback paths where the data rate stays under 2 Mbps.
2 Mbps data rate and 180 ns propagation delay — timing budget for isolated SPI
With a maximum propagation delay of 180 ns in each direction and pulse-width distortion capped at 8 ns, the ADUM1445ARQZ can clock isolated SPI at up to roughly 2.5 MHz (half the data rate) while keeping the clock-to-data skew within a single bit period. The 2 ns typical rise/fall time preserves signal integrity on short PCB traces, but the 180 ns delay means the designer must account for round-trip latency in closed-loop control loops or acknowledge-based protocols. The 25 kV/µs common-mode transient immunity (CMTI) ensures the isolation barrier holds up in noisy environments like motor drives or inverter stages where fast switching edges couple across the barrier.
Package, supply, and temperature grade
Housed in a 16-lead QSOP (the supplier device package is 16-QSOP, the package/case is 16-SSOP with 0.154" body width), this is a surface-mount part intended for reflow assembly. Supply voltage tolerance of 2.25 V to 3.6 V on each side means a single 3.3 V rail powers both sides, or a 2.5 V core domain can talk to a 3.3 V peripheral domain without a secondary regulator.
Lifecycle and compliance
No second-source cross-reference is documented in the manufacturer's literature, but the iCoupler family includes functionally similar parts with different channel counts or direction ratios — for example, the ADUM1441ARQZ-RL7 offers a 3/1 input-side/side-2 split for mixed-direction isolation.