MCP23008-E/P

Overview

The MCP23008-E/P is an 8-bit I/O expander featuring an I2C serial interface, housed in an 18-pin PDIP package. It operates within a supply voltage range of 1.8V to 5.5V and supports clock frequencies up to 1.7 MHz. The device provides eight bidirectional GPIO pins with configurable interrupt outputs and internal pull-up resistors. Designed for industrial environments, it functions reliably between -40°C and +125°C.

Feature Summary

• Provides 8-bit remote bidirectional I/O expansion via the I2C bus.
• Features configurable interrupt output with active-high, active-low, or open-drain modes.
• Includes hardware address pins to support multiple devices on a single bus.
• Supports external reset input and polarity inversion for input data.

Applications

• Embedded systems requiring additional GPIO ports.
• Industrial control panels with limited microcontroller pins.
• Smart home automation interfaces.
• Sensor network nodes requiring interrupt-driven data acquisition.

Procurement Notes

Verify the specific suffix 'E/P' corresponds to the PDIP package and industrial temperature grade (-40°C to +125°C). Confirm that the I2C interface is required, as the SPI variant (MCP23S08) uses different pinouts. Ensure the host system supports the necessary I2C addressing scheme using the three hardware address pins.

Selection Notes

Select this component when an I2C interface is preferred over SPI for board space efficiency. The PDIP package is suitable for through-hole prototyping or applications requiring manual insertion. Consider the MCP23017 if sixteen I/O channels are needed, noting the difference in package size and pin count.

Part Context

This part belongs to the MCP23X08 family of 8-bit I/O expanders from Microchip Technology. It shares architectural similarities with the MCP23S08 but utilizes an I2C interface instead of SPI. The family is designed for general-purpose parallel I/O expansion in resource-constrained embedded applications.

Replacement Considerations

The MCP23008T-E/ML is a surface-mount alternative in a QFN-20 package. Verify compatibility regarding pinout differences and thermal management requirements when substituting through-hole parts with surface-mount variants.

FAQ

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

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

What is the default state of the I/O pins upon power-up?

All I/O pins default to input mode after a Power-on Reset (POR) event.

Can the interrupt output be configured for different polarities?

Yes, the INT pin can be configured as active-high, active-low, or open-drain via the IOCON register.