The PCA9534A open-drain interrupt (INT) 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. INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I2C bus. Thus, the PCA9534A can remain a simple slave device. The device's outputs (latched) have high-current drive capability for directly driving LEDs. It has low current consumption.