What the MAX7310AUE+ does on the bus
The Maxim Integrated MAX7310AUE+ is an 8-bit I²C/SMBus port expander that gives a microcontroller eight extra GPIO pins over a two-wire serial bus. It runs at 400 kHz on the clock, matching the fast-mode ceiling of I²C, so it coexists on the same bus as sensors, EEPROMs, and other peripherals without needing a slower divider. The POR feature means the outputs power up in a known state — no glitches on relays or LEDs during a brown-out recovery.
Supply range and temperature — where it fits
That alone can save a BOM line and a few square millimetres of board space.
Output drive and I/O flexibility
Each of the eight I/Os can be configured as open-drain or push-pull. No interrupt output is provided — if your MCU needs edge-triggered attention, the host polls the expander over I²C or you add a separate interrupt controller.
Package and physical fit
Housed in a 16-TSSOP (4.40 mm width) package, it mounts on the surface of a standard PCB with a 0.65 mm pitch. The ROHS3 compliance means no lead, mercury, or cadmium — no exemption paperwork needed for EU markets.
Lifecycle status — still in production
For new designs, there is no end-of-life risk in the near term.