PCAL6524 Ultra-Low Voltage I/O Expanders NXP PCAL6524 Ultra-Low Voltage I/O Expanders provide remote I/O expansion for most microcontrollers using a Fast-mode Plus (Fm+) I2C-bus interface. The PCAL6524 24-bit general purpose I/O expanders have an ultra-low-voltage interface for direct connection to microcontrollers. NXP I/O expanders are a simple solution for when additional I/Os are needed while keeping interconnections to a minimum. This is particularly good for battery-powered mobile applications for interfacing to sensors, push buttons and keypads.Learn more