MAX7321:I2C Port Expander with 8 Open-Drain I/Os

An 8 Push-Pull Output GPIO/LED Driver with an RST Input Software Compatible with the MAX7324, MAX7325, MAX7326 and MAX7327 (16-Port GPIOs)

The MAX7321 2-wire serial-interfaced peripheral features eight open-drain I/O ports with selectable internal pullups and transition detection. Any port may be used as a logic input or an open-drain output. Ports are overvoltage protected to +6V independent of supply voltage. All I/O ports configured as inputs are continuously monitored for state changes (transition detection). State changes are indicated by the open-drain, active-low INT output. The interrupt is latched, allowing detection of transient changes. When the MAX7321 is subsequently accessed through the serial interface, any pending interrupt is cleared. The open-drain outputs are rated to sink 20mA and are capable of driving LEDs. The +6V tolerant active-low RST input clears the serial interface, terminating any I2C communication to or from the MAX7321. The MAX7321 uses two address inputs with four-level logic to allow 16 I2C slave addresses. The slave address also determines the power-up logic state for the I/O ports, and enables or disables internal 40kΩ pullups in groups of four ports. The MAX7321 is one device in a family of pin-compatible port expanders with a choice of input ports, open-drain I/O ports, and push-pull output ports. The MAX7321 is available in 16-pin QSOP and TQFN packages, and is specified over the automotive temperature range (-40°C to +125°C).

Key Features
  • 400kHz I2C Serial Interface
  • +1.71V to +5.5V Operating Voltage
  • 8 Open-Drain I/O Ports Rated to 20mA Sink Current
  • I/O Ports Are Overvoltage Protected to +6V
  • Any Port Can Be a Logic Input or an Open-Drain Output
  • Selectable I/O Port Power-Up Default Logic States
  • Transient Changes Are Latched, Allowing Detection Between Read Operations
  • active-low INT Output Alerts Change on Inputs
  • AD0 and AD2 Inputs Select from 16 Slave Addresses
  • Low 0.6µA (typ) Standby Current
  • -40°C to +125°C Operating Temperature
MAX7321: Typical Operating Circuit
MAX7321: Typical Operating Circuit
  • Cell Phones
  • Notebooks
  • Satellite Radio
  • Servers
titleDownload file
MAX7321 Data SheetMAX7321.pdf
Part NumberInterfaceI/OReset InputInterr.OutOver Voltage Protection
Drive Current
minmaxSee Notes
MAX7321Serial 2-Wire 400kbit8YesYes6201.715.5QSOP/16
$1.18 @1k
Design kits & evaluation modules
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX7321AEENo Longer AvailableMAX7321AEE+QSOP,;16 pin;30.9 mm²-40°C to +125°CNo
MAX7321AEE+ActiveQSOP,;16 pin;30.9 mm²-40°C to +125°CLead Free
MAX7321AEE+TActiveQSOP,;16 pin;30.9 mm²-40°C to +125°CLead Free
MAX7321AEE-TNo Longer AvailableMAX7321AEE+TQSOP;16 pin-40°C to +125°CSee data sheet
MAX7321ATENo Longer AvailableMAX7321ATE+TQFN,;16 pin;9.6 mm²-40°C to +125°CNo
MAX7321ATE+ActiveTQFN,;16 pin;9.6 mm²-40°C to +125°CLead Free
MAX7321ATE+TActiveTQFN,;16 pin;9.6 mm²-40°C to +125°CLead Free
MAX7321ATE-TNo Longer AvailableMAX7321ATE+TQFN;16 pin-40°C to +125°CSee data sheet
MAX7321.pdf MAX7321
MAX7321_cn.pdf MAX7321
MAX7321.pdf MAX7321
MAX7321.pdf MAX7321
MAX7321.pdf MAX7321
MAX7321_cn.pdf MAX7321