MCP23009-E/MGVAO

Overview

The MCP23009-E/MGVAO is an 8-bit I/O expander featuring an I2C interface, manufactured by Microchip Technology. It operates within a 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. It includes configurable interrupt outputs, internal pull-up resistors, and polarity inversion registers. The component is housed in a 16-lead QFN package (3x3x0.9 mm) and is qualified under AEC-Q100 standards for automotive applications.

Feature Summary

• AEC-Q100 qualified for automotive reliability
• Configurable interrupt-on-change functionality
• Hardware address pin for multi-device bus support
• Open-drain outputs with 5.5V tolerance

Applications

• Automotive embedded control systems
• Multi-device I2C peripheral expansion
• Industrial digital input/output modules

Procurement Notes

Verify the specific suffix MGVAO against official Microchip documentation to confirm tape-and-reel packaging and automotive grade qualification. Ensure the ordering code matches the exact temperature range and package variant required for your design. Cross-reference the datasheet revision to confirm register definitions and electrical characteristics remain consistent with your integration plan.

Selection Notes

Select this component when an I2C interface is preferred over SPI for GPIO expansion in space-constrained designs. The single hardware address pin allows up to eight devices on one bus without additional logic. Verify that the open-drain output configuration meets the load requirements of your connected peripherals, as push-pull outputs are not available.

Part Context

This part belongs to the MCP23X09 family, which also includes the SPI-based MCP23S09. Both share identical register maps and GPIO capabilities but differ in serial communication protocols. The MCP23009 variant utilizes the I2C bus, requiring SCL and SDA lines, while the MCP23S09 uses CS, SCK, SI, and SO lines.

Replacement Considerations

The MCP23S09 serves as a functional equivalent if SPI connectivity is required instead of I2C. Other generic I2C GPIO expanders may be considered if pin compatibility and register mapping allow for software adaptation. Verify that any substitute maintains the 1.8V to 5.5V operating voltage range and AEC-Q100 qualification if used in automotive contexts.

FAQ

How does the ADDR pin function on the MCP23009?

The ADDR pin acts as a voltage input that determines the three least significant bits of the 7-bit client address. This allows up to eight MCP23009 devices to coexist on a single I2C bus using only one microcontroller pin.

What is the purpose of the INTCC bit in the IOCON register?

The INTCC bit configures how interrupts are cleared. When set, reading the INTCAP register clears the interrupt; when cleared, reading the GPIO register clears the interrupt.

Can the MCP23009 operate in both Byte and Sequential modes?

Yes, the SEQOP bit in the IOCON register enables or disables automatic address pointer incrementing. Sequential mode increments the pointer after each byte, while Byte mode keeps it fixed for repeated access to the same register.