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MAX7328, MAX7329

I²C Port Expanders with Eight I/O Ports

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Status Explanations for product status codes

Part Number Status
MAX7328 Active: In Production. See Ordering Information for details.
MAX7329 Active: In Production. See Ordering Information for details.


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).

Data Sheet

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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)
  • -40°C to +125°C Automotive Temperature Range
  • Second Sources to PCF8574 and PCF8574A


  • Automotive
  • Industrial
  • Notebooks
  • RAID
  • Servers

Key Specifications:

I/O Port Expanders
Part Number Interface I/O Interr.Out Over Voltage Protect. Drive Current
min max See Notes
Serial - I2C Compatible
Serial 2-Wire 400kbit
8 Yes 5.5V 25 2.5 5.5 -
MAX7329  $1.08 @1k
See All I/O Port Expanders (35)

Pricing Notes:

This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.


MAX7328, MAX7329: Typical Application Circuit
Typical Application Circuit

More Information

New Product Press Release 2005-11-01

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Document Ref.: 19-3829 Rev 0; 2005-11-03
This page last modified: 2010-05-19