The PCA9538 is a 16-pin CMOS device that provides 8 bits of General Purpose parallel
Input/Output (GPIO) expansion with interrupt and reset for I2C-bus/SMBus applications
and was developed to enhance the NXP Semiconductors family of I2C-bus I/O expanders.
I/O expanders provide a simple solution when additional I/O is needed for ACPI power
switches, sensors, push-buttons, LEDs, fans, etc.