The Microchip Technology MCP23X17 family is a 28-pin, 16-channel, surface mount SOIC package general purpose parallel I/O expander. It has an electric rating ranging between 1.8V and 5.5V. It 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 (IODIRA/B). 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 the registers can be read by the system master. This device is used in industries.

• 25mA sink/source capability per I/O
• Cascadable for up to 8 devices on one bus
• Configurable interrupt source
• External reset input
• High speed I2C Interface at 400KHz frequency
• INTA and INTB can be configured to operate independently or together
• Operating temperature ranges between -40°C and 85°C
• Polarity inversion register to configure the polarity of the input port data
• Supports up to 10MHz SPI clock speeds