The PCAL6408APWJ is an 8-bit I/O Expander that provides remote I/O expansion for most microcontroller families via the I²C-bus interface. The NXP I/O expander provides a simple solution when additional I/Os are needed while keeping interconnections to a minimum. In addition to providing a flexible set of GPIOs, it simplifies interconnection of a processor running at one voltage level to I/O devices operating at a different (usually higher) voltage level. The PCAL6408A has built-in level shifting feature that makes this device extremely flexible in mixed signal environments where communication between incompatible I/O voltages is required. Its wide VDD range of 1.65 to 5.5V on the dual power rail allows seamless communications with next-generation low voltage microprocessors and microcontrollers on the interface side (SDA/SCL) and peripherals at a higher voltage on the port side.
