MCP23009-E/SS

Overview

The MCP23009-E/SS is an 8-bit I/O expander featuring an I2C interface, housed in a 20-lead SSOP package. It operates within a voltage range of 1.8V to 5.5V and supports I2C clock frequencies up to 3.4MHz. The device provides eight bidirectional GPIO pins with open-drain outputs capable of sinking 25mA per pin and 200mA total. Inputs are 5.5V tolerant. Key features include configurable interrupt-on-change, polarity inversion registers, internal pull-up resistors, and a hardware address pin allowing up to eight devices on the bus.

Feature Summary

• Provides 8-bit remote bidirectional I/O expansion via I2C interface
• Features configurable interrupt output with interrupt-on-change capability
• Includes hardware address pin for multi-device bus addressing
• Supports input polarity inversion and internal pull-up resistor configuration

Applications

• General purpose parallel I/O expansion for microcontroller systems
• Multi-device I2C bus configurations requiring hardware address selection
• Systems requiring interrupt-driven input state monitoring

Procurement Notes

Verify the ordering suffix matches the required package type and temperature grade. Confirm the specific revision level against the manufacturer's latest documentation to ensure compatibility with existing designs. Check for any recent product change notices that may affect pinout or electrical characteristics before finalizing procurement orders.

Selection Notes

Select this component when an I2C interface is preferred over SPI for I/O expansion. Ensure the system voltage falls within the 1.8V to 5.5V operating range. Consider the 20-lead SSOP package constraints regarding board space and thermal dissipation. Verify that the required number of I/O pins does not exceed the eight available channels.

Part Context

This part belongs to the MCP23X09 family, which includes both I2C (MCP23009) and SPI (MCP23S09) variants. The primary distinction between these variants is the serial communication interface used for register access and control. All other functional blocks, including the GPIO port and interrupt logic, remain identical across the family.

Replacement Considerations

Direct substitutes include other MCP23009 variants with different packages such as MCP23009-E/SO or MCP23009-E/P. Ensure the replacement maintains the same I2C interface and pinout compatibility if a direct drop-in replacement is required.