The MCP23X18 device provides 16-bit, general purpose parallel I/O expansion for I2C bus or SPI applications. The two devices differ only in the serial interface.
• MCP23018 - I2C interface
• MCP23S18 - SPI interface
The MCP23X18 consists of multiple 8-bit configuration registers for input, output and polarity selection. The system master can enable the I/Os as either inputs or outputs by writing the I/O configuration bits. The data for each input or output is kept in the corresponding input or output register. The polarity of the input port register can be inverted with the polarity inversion register. All registers can be read by the system master.

 

• 16-bit remote bidirectional I/O port
• Open-drain outputs:
• 5.5V tolerant
• 25 mA sink
• 400 mA total current out
• Low standby current as low as 1 µA
• High-speed I2C™ interface up to 3.4MHz
• Single hardware address pin: Voltage input to allow up to eight devices on the bus
• Configurable interrupt output pins: Configurable as active-high, active-low or open-drain
• Low standby current:1 µA (typ.)