MAX7329:I²C Port Expanders with Eight I/O Ports

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 active-low 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 active-low 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 in the full data sheet).

Key Features
  • 100kHz, 5.5V-Tolerant, I2C-Compatible Serial Interface
  • 2.5V to 5.5V Operating Supply Voltage Range
  • Low-Standby-Current Consumption of 10µA (max)
  • I2C Bus-to-Parallel-Port Expander
  • Open-Drain Interrupt Output Active-Low INT
  • 8-Bit Remote I/O Port for the I2C Bus
  • Latched Outputs with High-Current-Drive Capability for Directly Driving LEDs
  • Address by Three Hardware Address Pins for Use of Up to Eight Devices (Up to 16 Using Both MAX7328/MAX7329)
  • Second Sources to PCF8574 and PCF8574A
MAX7328, MAX7329: Typical Application Circuit
MAX7328, MAX7329: Typical Application Circuit
  • Industrial
  • Notebooks
  • RAID
  • Servers
titleDownload file
MAX7328-MAX7329 Data SheetMAX7328-MAX7329.pdf
Part NumberInterfaceI/OInterr.OutOver Voltage Protection
Drive Current
minmaxSee Notes
MAX7328Serial - I2C Compatible
Serial 2-Wire 400kbit
$1.82 @1k
$1.22 @1k
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX7329AAP+ActiveSSOP,;20 pin;57.9 mm²-40°C to +125°CLead Free
MAX7329AAP+TActiveSSOP,;20 pin;57.9 mm²-40°C to +125°CLead Free
MAX7329APPNo Longer AvailableTSSOP;-40°C to +125°CSee data sheet
MAX7329AWENo Longer AvailableMAX7329AWE+SOIC(W),;16 pin;111.8 mm²-40°C to +125°CNo
MAX7329AWE+ActiveSOIC(W),;16 pin;111.8 mm²-40°C to +125°CLead Free
MAX7329AWE+TActiveSOIC(W),;16 pin;111.8 mm²-40°C to +125°CLead Free
MAX7329AWE-TNo Longer AvailableMAX7329AWE+TSOIC(W),;16 pin;111.8 mm²-40°C to +125°CNo
MAX7328-MAX7329.pdf MAX7329
MAX7328-MAX7329_cn.pdf MAX7329
MAX7328-MAX7329_cn.pdf MAX7329