MICROCHIP MCP23017-E/SP 16-bit I/O Expander, I2C, PDIP-28

The MICROCHIP MCP23017-E/SP is a highly versatile 16-bit I/O port expander, designed to provide remote bidirectional input/output capabilities via a high-speed I²C bus interface. This integrated circuit is an essential component for projects requiring additional I/O pins beyond those available on a microcontroller, enabling significant expansion of control and monitoring functions in a compact format.

At its core, the device features multiple 8-bit configuration registers that allow precise control over input, output, and polarity selection. The system master (such as a microcontroller) can dynamically configure each of the 16 I/O pins as either an input or an output by writing to the I/O direction registers (IODIRA/B). Data for each port is stored in corresponding input or output registers, and the polarity of the input data can be conveniently inverted using the dedicated polarity inversion register, offering great flexibility for interfacing with different logic levels.

A key feature is the configurable interrupt system. The interrupt output pins, INTA and INTB, can be set to operate independently or be tied together, and the interrupt source itself is configurable. This allows for efficient, event-driven system design, reducing the need for constant polling of the I/O lines. Three hardware address pins enable up to eight identical devices to share the same I²C bus, maximising system expandability. Additional features include an external reset input and an impressively low standby current of just 1 μA maximum, making it suitable for power-sensitive applications.

Housed in a robust 28-pin PDIP (Plastic Dual In-line Package), the MCP23017-E/SP is designed for easy prototyping and integration into through-hole boards. Its wide operating voltage range from 1.8V to 5.5V ensures compatibility with both 3.3V and 5V logic systems, while its extended industrial temperature range from -40°C to 125°C guarantees reliable performance in a