Like the PCA962x family, the PCA963x devices have 7 hardware address pins that allow up to 124 PCA963x devices to be connected to the same I2C-bus and to be individually programmed. Both the PCA962x and PCA963x families of devices have a fast-mode plus I2C interface with a clock frequency up to 1MHz. Also, both families of devices are software compatible which makes it easier to interchange the devices or port the software from one system to another.