The PCA9575 is a CMOS device that provides 16 bits of General Purpose parallel Input/Output (GPIO) expansion in low voltage processor and handheld battery powered mobile applications and was developed to enhance the NXP family of I2C-bus I/O expanders. The improvements include lower supply current, lower operating voltage of 1.1 V to 3.6 V, separate supply rails to allow voltage level translation anywhere between 1.1 V and 3.6 V, 400 kHz clock frequency, and smaller packaging. Any of the 16 I/O ports can be configured as an input or output independent of each other and default on start-up to inputs.