NXP 8-Channel I/O Expander I2C 16-Pin SO16, PCF8574AT/3,518

The NXP bidirectional I2C bus (serial clock (SCL), serial data (SDA)). The devices consist of eight quasi bidirectional ports, 100 kHz I2C bus interface, three hardware address inputs and interrupt output operating between 2.5 V and 6 V. The quasi bidirectional port can be independently assigned as an input to monitor interrupt status or keypads, or as an output to activate indicator devices such as LEDs.

Latched outputs directly drive LEDs
Total package sink capability of 80 mA
Active low open-drain interrupt output