MCP23018-E/SS

I/o Expanders Overview

The MCP23018-E/SS is a Microchip Technology I/O expander featuring a 16-bit bidirectional port with open-drain outputs. It utilizes an I2C interface supporting 100 kHz, 400 kHz, and 3.4 MHz speeds. The device operates on a supply voltage ranging from 1.8 V to 5.5 V. It provides 25 mA sink capability per pin and up to 400 mA total. The component includes configurable interrupt outputs (INTA, INTB) and a hardware address pin for bus expansion. It is housed in a 24-pin SSOP package and supports an operating temperature range of -40°C to +125°C.

I/o Expanders Feature Summary

• Supports high-speed I2C communication with multiple clock frequency options
• Features configurable interrupt-on-change and interrupt-on-default mechanisms
• Includes a single hardware address pin allowing up to eight devices on the bus
• Provides open-drain outputs tolerant to 5.5V with individual pull-up resistor configuration

I/o Expanders Applications

• Remote I/O expansion for microcontroller systems
• Embedded control interfaces requiring additional digital inputs and outputs
• Industrial automation systems needing reliable I/O expansion over I2C buses

I/o Expanders Procurement Notes

Verify the specific ordering suffix matches the required package type. Confirm that the 'E' designation aligns with the intended industrial temperature range specifications. Ensure the I2C interface requirement is met, as this variant does not support SPI. Cross-reference the datasheet revision to confirm register definitions match the design implementation.

I/o Expanders Selection Notes

Select this component when an I2C interface is preferred over SPI for system integration. Consider the 24-pin SSOP package constraints regarding board space and thermal dissipation. Evaluate the need for the extended temperature range if the application environment exceeds standard commercial limits. Verify that the open-drain output characteristics suit the load requirements without external buffering.

I/o Expanders Part Context

This part belongs to the MCP23018/MCP23S18 family of 16-bit I/O expanders. The MCP23018 specifically denotes the I2C interface variant, distinguishing it from the MCP23S18 which uses SPI. The family shares identical GPIO functionality and register maps, differing only in the serial communication protocol and associated pinouts.

I/o Expanders Replacement Considerations

MCP23018T-E/SS: Tape and reel version of the same component.

I/o Expanders FAQ

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

Up to eight devices can be connected to the bus by configuring the voltage levels on the single hardware address pin.

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

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

Can the interrupt outputs be configured for different polarities?

Yes, the INTA and INTB pins can be configured as active-high, active-low, or open-drain via the IOCON register.