MCP23S18-E/SP

I/o Expanders Overview

The MCP23S18-E/SP is a Microchip Technology I/O expander featuring a 16-bit bidirectional port with open-drain outputs. It utilizes an SPI interface operating at up to 10 MHz for VDD between 2.7V and 5.5V, while supporting a broader supply range of 1.8V to 5.5V. The device provides 25 mA sink capability per pin and 400 mA total. It includes configurable interrupt outputs (INTA, INTB) triggered by pin changes or default value mismatches. Packaged in a 28-pin SOIC, it passes AEC-Q100 automotive reliability testing.

I/o Expanders Feature Summary

• Features a 16-bit remote bidirectional I/O port where pins default to input state.
• Provides open-drain outputs that are 5.5V tolerant with high current sink capabilities.
• Supports high-speed SPI communication with configurable interrupt output pins.
• Includes an external reset input and low standby current consumption.

I/o Expanders Applications

• Embedded systems requiring parallel I/O expansion via serial interfaces
• Automotive electronics applications meeting AEC-Q100 standards
• Industrial control systems utilizing SPI-based microcontrollers

I/o Expanders Procurement Notes

Verify the specific suffix 'E/SP' against the manufacturer's official documentation to confirm the package type and temperature grade. Ensure the ordering information matches the exact datasheet revision DS20002103B. Confirm availability through authorized Microchip distributors or direct factory channels.

I/o Expanders Selection Notes

Select this component when an SPI interface is required instead of I2C, as offered by the MCP23018 variant. Consider the 28-pin SOIC package constraints and the need for open-drain outputs. Verify that the system voltage supports the 1.8V minimum and that the SPI clock speed requirements do not exceed 10 MHz at lower supply voltages.

I/o Expanders Part Context

This part belongs to the MCP23X18 family, which also includes the I2C-compatible MCP23018. Both share identical register maps and functionality, differing only in the serial communication protocol. The MCP23S18 specifically targets designs using SPI buses, eliminating the need for hardware address pins used in the I2C version.

I/o Expanders Replacement Considerations

The MCP23018 serves as a functional equivalent if the application can support I2C instead of SPI. Other Microchip GPIO expanders may require significant register mapping adjustments due to different architecture or feature sets.

I/o Expanders FAQ

Does the MCP23S18 have a hardware address pin?

No, the MCP23S18 uses an SPI interface and does not have a hardware address pin. Addressing is handled via the SPI chip select (CS) line.

What is the maximum SPI clock frequency?

The maximum SPI clock frequency is 10 MHz, but this is specified for a supply voltage (VDD) between 2.7V and 5.5V.

Can the interrupt pins be configured?

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