MCP23008-E/SS

Overview

The MCP23008-E/SS is an 8-bit I/O expander with an I2C interface, housed in a 20-pin SSOP package. It operates on a supply voltage of 1.8V to 5.5V and supports clock frequencies up to 1.7 MHz. The device provides eight bidirectional GPIO pins (GP0-GP7) with configurable input/output directions and internal weak pull-up resistors. It features a configurable interrupt output pin that can be set as active-high, active-low, or open-drain. The component includes hardware address pins A0-A2 for bus addressing and an external reset input.

Feature Summary

• Provides 8-bit remote bidirectional I/O expansion via the I2C serial interface.
• Features a configurable interrupt output pin supporting active-high, active-low, or open-drain modes.
• Includes hardware address pins to allow multiple devices on the same bus.
• Contains registers for input polarity inversion and internal weak pull-up resistor configuration.

Applications

• General purpose parallel I/O expansion for microcontroller systems.
• Embedded systems requiring additional digital input and output ports.
• Applications utilizing I2C bus communication protocols.

Procurement Notes

Verify the specific ordering suffix matches the required package type and temperature range. Confirm the manufacturer identification aligns with Microchip Technology specifications. Ensure the component meets the necessary environmental and electrical standards for the intended deployment environment before finalizing procurement orders.

Selection Notes

Select this model when an I2C interface is preferred over SPI for I/O expansion. The SSOP package is suitable for surface-mount applications requiring a compact footprint. Consider the 1.8V to 5.5V operating voltage range to ensure compatibility with the system power supply. Verify that the three hardware address pins meet the addressing requirements for the target I2C bus topology.

Part Context

This component belongs to the MCP23X08 family of 8-bit I/O expanders. It shares functional similarities with the MCP23S08, which utilizes an SPI interface instead of I2C. Both variants provide identical GPIO capabilities but differ in their serial communication protocols and hardware address pin configurations.

Replacement Considerations

The MCP23S08 serves as a functional alternative if SPI connectivity is required instead of I2C. Other members of the MCP23X08 family may offer different package options or interface types while maintaining similar GPIO expansion functionality.

FAQ

How are the I2C slave addresses determined?

The 7-bit slave address is composed of four fixed bits and three user-defined hardware address bits corresponding to pins A2, A1, and A0.

What is the function of the INT pin?

The INT pin is a configurable interrupt output that signals the system master when an input state changes or differs from a configured default value.

Can the input polarity be inverted?

Yes, the IPOL register allows the user to configure the polarity of the input port data, enabling inversion of the logic state read by the GPIO register.