CAT9555

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. The CAT9555 features an active low interrupt output which indicates to the system master that an input state has changed. The three address input pins provide the device’s extended addressing capability and allow up to eight devices to share the same bus. The fixed part of the I2C slave address is the same as the CAT9554, allowing up to eight of these devices in any combination to be connected on the same bus. Features 400 kHz I2C Bus Compatible 2.3 V to 5.5 V Operation Low Stand−by Current 5 V Tolerant I/Os 16 I/O Pins that Default to Inputs at Power−up High Drive Capability Individual I/O Configuration Polarity Inversion Register Active Low Interrupt Output Internal Power−on Reset No Glitch on Power−up Noise Filter on SDA/SCL Inputs ...