The TCA9534 is a 16-pin device that provides 8 bits of general purpose parallel input and output (I/O) expansion for the two-line bidirectional I2C bus (or SMBus) protocol. The device can operate with a power supply voltage ranging from 1.65 V to 5.5 V, which allows for use with a wide range of devices. The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. I/O expanders such as the TCA9534 provide a simple solution when additional I/Os are needed for switches, sensors, push-buttons, LEDs, fans, and other similar devices. The features of the TCA9534 include an interrupt that is generated on the INT pin. This allows the master to know when an input port changes state. The A0, A1, and A2 hardware selectable address pins allow up to eight TCA9534 devices on the same I2C bus. The device can also be reset to its default sate by cycling the power supply and causing a power-on reset.