The MAX7300 compact, serial-interfaced, I/O expansion peripheral provides microprocessors with up to 28 ports. Each port is individually user configurable to either a logic input or logic output.
Each port can be configured as either a push-pull logic output capable of sinking 10mA and sourcing 4.5mA, or a Schmitt logic input with optional internal pullup. Seven ports feature configurable transition detection logic, which generates an interrupt upon change of port logic level. The MAX7300 is controlled through an I²C-compatible 2-wire serial interface, and uses four-level logic to allow 16 I²C addresses from only two select pins.
The MAX7300AAX and MAX7300ATL have 28 ports and are available in 36-pin SSOP and 40-pin thin QFN packages, respectively. The MAX7300AAI and MAX7300ATI have 20 ports and are available in 28-pin SSOP and thin QFN packages. For an SPI™-interfaced version, refer to the MAX7301 data sheet. For a pin-compatible port expander with additional 24mA constant-current LED drive capability, refer to the MAX6956 data sheet.