MAX7312AAG+

Overview

The MAX7312AAG+ is a 2-wire-interfaced 16-bit I/O port expander designed for SMBus and I2C applications. It provides 16 configurable input/output pins that default to inputs upon power-up, alongside an open-drain interrupt output (INT). The device operates within a supply voltage range of 2V to 5.5V and supports a serial clock frequency up to 400kHz. It features 5V overvoltage tolerant I/Os, hot-insertion support with high-impedance states up to 6V when powered down, and bus timeout functionality for lock-up-free operation. The component is housed in a 24-pin SSOP package and is specified for operation across an extended temperature range of -40°C to +125°C.

Feature Summary

• Configurable 16-bit parallel I/O expansion via I2C-compatible serial interface
• Supports hot insertion with high-impedance protection on all pins when powered down
• Includes polarity inversion registers and bus timeout logic for system reliability

Applications

• Servers and server blades
• RAID systems
• Medical equipment
• Instrumentation and test measurement devices
• Networking hardware

Procurement Notes

Verify the specific ordering suffix 'AAG' corresponds to the 24-pin SSOP package variant as listed in the official Maxim Integrated datasheet. Confirm that the '+' suffix indicates lead-free compliance if required by your assembly specifications. Ensure the supplier provides documentation matching the Rev 3 datasheet dated April 2005 to guarantee parameter accuracy.

Selection Notes

Select this component when a microcontroller requires additional general-purpose I/O lines accessible via standard I2C or SMBus protocols. It is suitable for designs needing 5V tolerant inputs regardless of the core logic voltage, provided the supply remains between 2V and 5.5V. Consider the 24-pin SSOP form factor for space-constrained PCB layouts requiring through-hole or surface-mount compatibility with standard footprints.

Part Context

The MAX7312 belongs to the Maxim Integrated GPIO expander family, offering parallel port expansion for serial buses. It complements other expanders like the MAX7311, which includes integrated pullup resistors. The device utilizes BiCMOS technology and contains approximately 12,994 transistors, enabling low standby current consumption while maintaining robust noise filtering on the SCL and SDA inputs.

Replacement Considerations

Direct pin-to-pin replacements include the MAX7312AWG (Wide SO), MAX7312ATG (Thin QFN), and MAX7312AUG (TSSOP), which share identical electrical characteristics and register maps but differ in physical package dimensions.