MCP23008T-E/SO

Overview

The MCP23008T-E/SO is an 8-bit I/O expander featuring an I2C interface, housed in an 18-pin SOIC package. It operates within a supply voltage range of 1.8V to 5.5V and supports clock frequencies up to 1.7MHz. The device includes three hardware address pins (A2, A1, A0) allowing up to eight devices on the bus. Key electrical parameters include a maximum standby current of 1µA, output sink/source capability of 25mA per pin, and an operating temperature range from -40°C to +125°C.

Feature Summary

• Provides 8-bit remote bidirectional I/O expansion via high-speed I2C serial interface.
• Features configurable interrupt outputs with interrupt-on-change or default value comparison capabilities.
• Includes internal weak pull-up resistors and polarity inversion registers for input port data configuration.

Applications

• General purpose parallel I/O expansion for microcontroller systems.
• Embedded control applications requiring additional digital inputs and outputs.
• Industrial automation interfaces utilizing I2C communication protocols.

Procurement Notes

Verify the specific suffix 'SO' confirms the 18-pin SOIC package type during ordering. Ensure the 'E' grade designation matches the required industrial temperature range specifications. Confirm that the I2C interface requirement aligns with the system master's serial bus capabilities rather than SPI alternatives.

Selection Notes

Select this component when an I2C interface is preferred over SPI for I/O expansion. Consider the 18-pin SOIC package constraints regarding PCB space and thermal dissipation. Evaluate the need for multiple devices on the bus, as the three address pins support up to eight units. Verify power supply stability within the 1.8V to 5.5V range for reliable operation.

Part Context

This part belongs to the MCP23X08 family of 8-bit I/O expanders. It differs from the MCP23S08 variant by utilizing an I2C interface instead of SPI and supporting three hardware address pins compared to two. The device shares similar register structures and interrupt logic with other members of the series but is distinct in its serial communication protocol.

Replacement Considerations

The MCP23008T-I/SO serves as a commercial temperature grade alternative. For SPI interface requirements, the MCP23S08T-E/SO is the functional equivalent with adjusted addressing. Direct pin-compatible replacements should be verified against specific package dimensions and electrical characteristics.

FAQ

How many devices can be addressed on a single I2C bus using the MCP23008?

Up to eight devices can be connected to the same I2C bus, determined by the states of the three hardware address pins (A2, A1, and A0).

What is the function of the INT pin on the MCP23008?

The INT pin provides an interrupt output signal that can be configured as active-high, active-low, or open-drain to indicate input state changes or comparisons against default values.

Can the MCP23008 operate at temperatures above 85°C?

Yes, the '-E' grade version supports an extended operating temperature range up to +125°C, provided the supply voltage is maintained between 4.5V and 5.5V.