The MAX7328/MAX7329 are 2-wire serial-interfaced peripherals with eight I/O ports. Any port can be used as a logic input or an open-drain output. All input ports are continuously monitored for state changes (transition detection). Transitions are alerted through the open-drain, 5.5V-tolerant INT output. The MAX7328 and MAX7329 versions differ only by their slave ID address ranges. The MAX7328 has a slave ID range of 0100xxx (0x20 to 0x27). The MAX7329 has a slave ID range of 0111xxx (0x38 to 0x3F). For a similar part with overvoltage-protected I/Os and a bus RST input that clears the I2C* serial interface, refer to the MAX7321 data sheet. The MAX7328/MAX7329 are members of a family of pin-compatible port expanders with a choice of input ports, open-drain I/O ports, and push-pull output ports (see the Selector Guide).