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.
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.
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.