Microchip MCP23S08-E/SS SPI I/O Expander, 8-Bit, 20-Pin SSOP

The Microchip MCP23S08-E/SS is an 8-bit, general-purpose parallel input/output (I/O) expander designed for Serial Peripheral Interface (SPI) applications. This versatile IC provides a simple solution for adding extra digital I/O lines to a microcontroller or system master, effectively expanding its capabilities in space-constrained designs.

The device features multiple 8-bit configuration registers that allow the system master to individually enable each pin as either an input or an output. Data for these pins is stored in corresponding input or output registers. A key functionality is the polarity inversion register, which allows the logical state of the input port data to be inverted, adding flexibility for interfacing with different logic levels.

Engineered for robust performance, the MCP23S08 supports a high SPI clock speed of up to 10 MHz, enabling fast data transfer. It offers a strong 25 mA sink/source capability per I/O pin, allowing it to directly drive LEDs or other peripherals. The inclusion of an internal Power-On Reset (POR) and an external reset input ensures reliable start-up and system control. With a very low maximum standby current of just 1 µA, it is an excellent choice for power-sensitive and battery-operated applications.

Housed in a compact 20-pin SSOP package, it is ideal for industrial control systems, sensor arrays, and any embedded application requiring additional I/O. Its wide operating voltage range from 1.8V to 5.5V makes it compatible with a broad spectrum of logic families.