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CAT9554, CAT9554A
8-bit I2C and SMBus I/O Port with Interrupt
Description
The CAT9554 and CAT9554A are CMOS devices that provide 8−bit parallel input/output port expansion for I2C and SMBus compatible applications. These I/O expanders provide a simple solution in applications where additional I/Os are needed: sensors, power switches, LEDs, pushbuttons, and fans.
The CAT9554/9554A consist of an input port register, an output port register, a configuration register, a polarity inversion register and an I2C/SMBus−compatible serial interface.
Any of the eight I/Os can be configured as an input or output by writing to the configuration register. The system master can invert the CAT9554/9554A input data by writing to the active−high polarity inversion register.