PCAL9722HNMP is an ultra-low-voltage translating 22-bit SPI I/O expander with Agile I/O features, interrupt output, and reset. It provides remote I/O expansion for most microcontrollers with the SPI interface. The ultra-low-voltage interface allows for direct connection to a microcontroller operating down to 1.1V. It provides a simple solution when additional I/Os are needed while keeping interconnections to a minimum, for example, in battery-powered mobile applications for interfacing with sensors, push buttons, keypads, etc. In addition to providing a flexible set of GPIOs, it simplifies the interconnection of a processor running at one voltage level down to 1.1V to I/O devices operating at a different voltage level 1.65 to 5.5V.