The PCAL6408A is an 8-bit I²C GPIO expander with integrated interrupt and reset functionality, purpose-built to expand microcontroller I/O. Featuring built-in level shifting and a wide 1.65 V to 5.5 V operating range, it enables seamless communication across mixed-voltage systems. With advanced Agile I/O features and flexible package options, the PCAL6408A adapts to a wide range of applications. As a pin-to-pin drop-in replacement that is fully software backward-compatible with the PCA6408A, it offers a simple, reliable upgrade path for existing designs.