MCP23S18-E/MJ

I/o Expanders Overview

The MCP23S18-E/MJ is a 16-bit I/O expander with open-drain outputs, utilizing an SPI interface. It operates within a voltage range of 1.8V to 5.5V and supports clock frequencies up to 10 MHz. The device provides 16 bidirectional I/O pins, each capable of sinking 25 mA, with a total sink current of 400 mA. Inputs are 5.5V tolerant. It features configurable interrupt outputs (INTA/INTB) for pin change or default value deviation detection. The component is housed in a 24-pin QFN package and meets AEC-Q100 automotive reliability standards.

I/o Expanders Feature Summary

• Supports high-speed SPI communication with hardware addressability not required
• Provides 16-bit remote bidirectional I/O expansion with open-drain output configuration
• Features configurable interrupt logic for detecting input state changes or deviations from defaults
• Includes polarity inversion registers for input data manipulation

I/o Expanders Applications

• Automotive electronic control units requiring robust I/O expansion
• Industrial systems needing isolated digital input/output management
• Embedded controllers interfacing with peripheral devices via SPI bus

I/o Expanders Procurement Notes

Verify the specific suffix MJ corresponds to the 24-pin QFN package variant when sourcing. Confirm that the -E designation indicates the extended industrial temperature range suitable for your operational environment. Ensure the SPI interface requirements align with your host controller's capabilities before finalizing procurement.

I/o Expanders Selection Notes

Select this model over the MCP23018 if an SPI interface is preferred over I2C to avoid bus contention issues. Consider the 24-pin QFN package constraints regarding thermal dissipation and PCB layout space. Verify that the open-drain output characteristics meet the load requirements of your connected peripherals.

I/o Expanders Part Context

This component belongs to the MCP23x18 family, which includes both I2C (MCP23018) and SPI (MCP23S18) variants. The MCP23S18 specifically replaces the I2C interface with SPI, eliminating the need for hardware address pins while maintaining identical I/O functionality and register maps. It serves as a direct parallel expansion solution for microcontrollers lacking sufficient GPIO pins.

I/o Expanders Replacement Considerations

The MCP23S17 is a functional substitute offering similar 16-bit expansion but utilizes a 28-pin package instead of the 24-pin QFN form factor.