The PCA9534D is a 8-bit CMOS I2C-bus and SMBus low power I/O Port with interrupt provide 8-bit of general purpose parallel Input/Output (GPIO) expansion for I2C-bus/SMBus applications and was developed to enhance the semiconductors family of I2C-bus I/O expanders. The improvements include higher drive capability, 5V I/O tolerance, lower supply current, individual I/O configuration, 400kHz clock frequency and smaller packaging. I/O expanders provide a simple solution when additional I/O is needed for ACPI power switches, sensors, push buttons, LEDs and fans. The open-drain interrupt output is activated when any input state differs from its corresponding input port register state and is used to indicate to the system master that an input state has changed. The power-on reset sets the registers to their default values and initializes the device state machine.
