It operates across a 2V to 5.5V supply range, making it equally at home on 3.3V or 5V logic rails without level shifters. Each pin can source 31 mA or sink 43 mA — enough to drive LEDs, small relays, or signal-level loads directly. The interrupt output (IRQ) signals the host on pin-state changes, so the main MCU doesn't have to poll. With a 400 kHz clock rate, the bus transaction for a full port read or write completes in roughly 40 µs, which is fast enough for front-panel buttons, status LEDs, and sensor-bank multiplexing.
Industrial temperature range — not just a box-tick
The 125°C upper limit covers self-heating inside a sealed enclosure on a hot production floor. If your BOM runs at 85°C ambient with a 20°C rise inside the enclosure, you still have 20°C of margin before the part leaves its rated window.
Active lifecycle — no LTB scramble needed
For production builds, it can be dual-sourced against the PCA9535 family if the design already uses that footprint — the I²C address map and register layout differ, so a firmware change is required, but the pinout is compatible.
Package and handling notes
The 24-SOIC footprint is shared by many 16-bit I²C expanders, so board layout reuse across alternate sources is straightforward. No exposed pad — all dissipation goes through the leads.