MCP23009-E/P

Overview

The MCP23009-E/P is an 8-bit I/O expander featuring an I2C interface, housed in an 18-lead PDIP package. It operates within a voltage range of 1.8V to 5.5V and supports clock frequencies up to 3.4MHz. The device provides eight bidirectional GPIO pins with open-drain outputs capable of 25mA sink current per pin and 200mA total. Key features include configurable interrupt outputs, internal pull-up resistors, polarity inversion registers, 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 serial interface
• Features configurable interrupt output pins supporting active-high, active-low, or open-drain modes
• Includes internal pull-up resistors and polarity inversion registers for input port data configuration
• Supports multi-device bus addressing through a single hardware address pin

Applications

• General purpose parallel I/O expansion for microcontroller systems
• Key matrix scanning and LED array control
• Sensor enable signal management and digital input acquisition

Procurement Notes

Verify the specific ordering suffix matches the required package type, as the base part number covers multiple form factors. Confirm the temperature grade aligns with operational requirements. Ensure the I2C interface compatibility is validated against the host controller's serial bus specifications before finalizing procurement.

Selection Notes

Select this component when an I2C interface is preferred over SPI for I/O expansion. The PDIP package is suitable for through-hole prototyping or applications requiring manual assembly. Consider the 3.4MHz maximum clock speed and 5.5V tolerant inputs when interfacing with higher voltage logic systems.

Part Context

This device belongs to the MCP23X09 family, which includes both I2C (MCP23009) and SPI (MCP23S09) variants. The primary distinction lies in the serial communication protocol. The E designation indicates the industrial temperature range variant. The PDIP package offers a larger footprint compared to surface-mount options like QFN or SOIC.

Replacement Considerations

The MCP23S09 serves as the functional equivalent but utilizes an SPI interface instead of I2C. Other Microchip expanders like the MCP23017 offer 16 bits but differ in register architecture. Verify pinout compatibility and software library support when substituting.