General Description
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 TQFN packages, respectively. The MAX7300AAI and MAX7300ATI have 20 ports and are available in 28-pin SSOP and TQFN 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.

Features
♦ 400kbps I2C-Compatible Serial Interface
♦ 2.5V to 5.5V Operation
♦ -40°C to +125°C Temperature Range
♦ 20 or 28 I/O Ports, Each Configurable as
   Push-Pull Logic Output
   Schmitt Logic Input
   Schmitt Logic Input with Internal Pullup
♦ 11µA (max) Shutdown Current
♦ Logic Transition Detection for Seven I/O Ports

Applications
   White Goods
   Industrial Controllers
   Automotive
   System Monitoring