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CAT9555
16-bit I2C and SMBus I/O Port with Interrupt
Description
The CAT9555 is a CMOS device that provides 16−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 CAT9555 consists of two 8−bit Configuration ports (input or output), Input, Output and Polarity inversion registers, and an I2C/SMBus−compatible serial interface.
Any of the sixteen I/Os can be configured as an input or output by writing to the configuration register. The system master can invert the CAT9555 input data by writing to the active−high polarity inversion register.