Description
The PCA9554 is a CMOS device that provides 8−bit parallel input/output port expansion for I2C and SMBus compatible applications. This I/O expander provides a simple solution in applications where additional I/Os are needed: sensors, power switches, LEDs, pushbuttons, and fans.
The PCA9554 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 PCA9554 input data by writing to the active−high polarity inversion register.
The PCA9554 features an active low interrupt output which indicates to the system master that an input state has changed.
The device’s extended addressing capability allows up to 8 devices to share the same bus.

Features
• 400 kHz I2C Bus Compatible (Note 1)
• 2.3 V to 5.5 V Operation
• Low Standby Current
• 5 V Tolerant I/Os
• 8 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
• Cascadable up to 8 Devices
• Industrial Temperature Range
• 16−lead TSSOP Package
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant

Applications
• White Goods (dishwashers, washing machines)
• Handheld Devices (cell phones, PDAs, digital cameras)
• Data Communications (routers, hubs and servers)