Two-channel isolator with capacitive coupling — what the specs mean for your design
It provides one channel in each direction (1/1 unidirectional), so it fits interfaces like SPI where you need a clock going one way and data returning — no wasted channels. The 5 Mbps data rate and 70 ns max propagation delay (both directions) set the timing budget: for a 1 MHz SPI bus you have comfortable margin, but pushing toward 5 Mbps means accounting for the 70 ns latency plus the 3 ns pulse-width distortion in your setup/hold calculations.
Isolation and noise immunity — 2500 Vrms and 25 kV/µs CMTI
Rated for 2500 Vrms isolation, this part handles basic isolation in industrial drives, motor controls, and medical equipment where the barrier sees transient overvoltages but not sustained high-voltage DC. The 25 kV/µs common-mode transient immunity (minimum) means the output won't glitch when a motor drive switches a high-voltage rail — a spec that matters more than the isolation voltage for noisy environments.
No isolated power is built in, so you still need a separate DC/DC or isolated module to power the secondary side if the application requires fully isolated power domains.
For dual-sourcing resilience, the ISO7221 family includes the ISO7221B (same base number) — verify the exact suffix for your BOM, as the 'D' denotes the SOIC-8 package variant.