MCP23009T-E/MG

Overview

The MCP23009T-E/MG is an 8-bit I/O expander featuring an I²C interface, housed in a 16-lead QFN package (3x3x0.9 mm). It operates within a supply voltage range of 1.8V to 5.5V and supports clock frequencies up to 3.4 MHz. The device provides eight bidirectional GPIO pins with open-drain outputs capable of sinking 25 mA per pin and 200 mA total. Inputs are 5.5V tolerant. It includes configurable interrupt outputs, internal pull-up resistors, and polarity inversion registers. Operating temperatures span from -40°C to +125°C.

Feature Summary

• Supports multi-device addressing on the I²C bus via a single hardware address pin using an analog voltage divider method.
• Provides flexible interrupt handling with configurable sources, including interrupt-on-change against previous states or default values.
• Features individually configurable internal pull-up resistors for each GPIO pin to simplify external circuit design.

Applications

• Expanding general-purpose input/output capabilities in resource-constrained embedded systems.
• Managing multiple peripheral devices on a single I²C bus through hardware address decoding.
• Monitoring digital sensor inputs with automatic change detection and interrupt signaling.

Procurement Notes

Verify the specific suffix MG corresponds to the 16-lead QFN package and tape-and-reel shipping format. Confirm that the temperature grade E meets the required operational range for your application environment. Ensure compatibility with the host controller's I²C voltage levels and timing requirements before finalizing orders.

Selection Notes

Select this component when an I²C interface is preferred over SPI for board routing simplicity. The ADDR pin allows up to eight devices on one bus without additional logic gates. Consider the open-drain output limitation if active high drive current is required without external pull-ups. Verify power consumption constraints against the specified standby current ratings.

Part Context

This part belongs to the MCP23X09 family, which shares identical register maps and functionality except for the serial interface type. The MCP23S09 variant uses SPI instead of I²C. Both share the same GPIO architecture, interrupt mechanisms, and physical dimensions across compatible packages like QFN, SOIC, and PDIP.

Replacement Considerations

The MCP23S09 serves as a functional alternative if SPI connectivity is required instead of I²C. Other Microchip I/O expanders may offer different pin counts or interfaces but require software adaptation due to varying register structures.