8 input-only GPIO expander on the I2C bus
The MAX7319AEE+ is an I2C port expander from Analog Devices that provides 8 input-only GPIOs, each rated for 25 mA source/sink current. The 8 input-only I/O means this part is designed for reading switch states, sensor thresholds, or digital signals — it does not drive outputs. The interrupt output (IRQ) signals the host when any input changes, eliminating continuous polling on the I2C bus.
Supply voltage and temperature envelope
The 1.71 V minimum supply lets the expander run directly off a 1.8 V logic rail, common in low-power MCUs and SoCs. The POR (power-on reset) feature ensures the I/O states are initialized to a known condition after the supply crosses the threshold, so the host reads valid levels on first I2C access.
Package and board integration
Both are surface-mount, fine-pitch packages suited for compact PCB layouts. The tube packaging is typical for prototype and low-volume builds; for reflow assembly, the part is also available in tape-and-reel from the same series.