MCP23018-E/SO

I/o Expanders Overview

The MCP23018-E/SO is a 16-bit I/O expander featuring an I2C interface, housed in a 28-pin SOIC package. It operates within a voltage range of 1.8 V to 5.5 V and supports clock frequencies up to 3.4 MHz. The device provides two 8-bit ports (GPA and GPB) with open-drain outputs capable of 25 mA sink current per pin and 400 mA total. It includes configurable interrupt outputs, hardware address selection for up to eight devices on the bus, and passes Automotive AEC-Q100 reliability testing.

I/o Expanders Feature Summary

• Supports high-speed I2C communication with multiple frequency options
• Features configurable interrupt outputs triggered by pin changes or default value mismatches
• Includes a single hardware address pin allowing multiple devices on one bus
• Provides open-drain outputs tolerant to 5.5V

I/o Expanders Applications

• Embedded systems requiring parallel I/O expansion via serial buses
• Automotive electronics applications meeting AEC-Q100 standards
• Industrial control interfaces needing remote bidirectional I/O ports

I/o Expanders Procurement Notes

Verify the specific suffix 'E' indicates the industrial temperature grade (-40°C to +125°C) and 'SO' denotes the 28-pin SOIC package. Confirm RoHS compliance status through official Microchip documentation prior to ordering. Ensure the design accounts for the exposed thermal pad requirements if applicable to the layout.

I/o Expanders Selection Notes

Select this component when an I2C interface is required rather than SPI; use MCP23S18 for SPI applications. Consider the 28-pin SOIC package constraints against available PCB space. Verify that the system voltage levels align with the 1.8V to 5.5V operating range and that the 25mA per pin sink capability meets load requirements.

I/o Expanders Part Context

This part belongs to the MCP23X18 family of 16-bit I/O expanders. The MCP23018 variant specifically utilizes the I2C protocol, whereas the MCP23S18 uses SPI. Both share identical GPIO functionality and register maps but differ in their serial communication interfaces and addressing schemes.

I/o Expanders Replacement Considerations

MCP23S18-E/SO: Identical physical package and GPIO features but uses SPI instead of I2C. Requires significant firmware and hardware redesign to replace CS/SCK/SI/SO lines for SDA/SCL.

I/o Expanders FAQ

How many devices can be connected to a single I2C bus using the ADDR pin?

Up to eight devices can be connected to the same I2C bus by applying different voltage levels to the single hardware address pin.

What is the maximum sink current per output pin?

Each output pin is capable of sinking 25 mA, with a total device limit of 400 mA.

Does the MCP23018 support interrupt-on-change functionality?

Yes, the device supports interrupts triggered when an input state differs from its configured default value or when a pin change occurs.