I²C Port Expander with 16 I/O and Interrupt
The Maxim Integrated MAX7325AEG+ is an I²C port expander providing 16 I/O lines, of which 8 are configurable as output-only, in a 24-QSOP package. It communicates over the I²C bus at up to 400 kHz and includes a programmable reset (POR) feature for known startup states.
Output Drive and Interrupt — Design Decisions
Each I/O pin can sink or source 20 mA, configurable as open-drain or push-pull output. This drive capability handles LEDs, small relays, and logic-level translation directly without external buffers. The open-drain option is useful for wired-OR interrupt lines or level-shifting to a different supply voltage on the same bus. An interrupt output pin signals the host when an input changes state, reducing the need for constant I²C polling. The POR feature ensures all outputs initialize to a known high-impedance state on power-up, avoiding unintended glitches on downstream loads.
Housed in a 24-QSOP supplier package footprint.