Microchip MCP23008 I/O Expander, 8-Bit, I2C, 1.8V-5.5V, SSOP-20

The Microchip MCP23008-E/SS is an 8-bit general purpose parallel I/O expander designed for I²C bus applications. It provides a simple and efficient method for adding extra input/output ports to a microcontroller system via the popular I²C serial interface.

The device features multiple 8-bit configuration registers that allow the system master to individually set each of the eight I/O pins as either an input or an output. The state of each pin is stored in a corresponding input or output register, all of which can be read by the master. A dedicated polarity inversion register provides the flexibility to invert the logic level of the input port data, simplifying interface design with active-low signals.

Key Features & Specifications

• High Drive Capability: Each I/O pin can sink or source up to 25mA, allowing it to directly drive LEDs or other peripherals.
• Flexible I²C Clock Support: The device supports standard (100kHz), fast (400kHz), and high-speed (1.7MHz) I²C communication modes for optimal performance in various applications.
• Address Expansion: Three hardware address pins enable up to eight identical devices to share the same I²C bus, providing expansion for up to 64 additional I/O lines.
• Robust System Control: Features include an internal power-on-reset (POR) circuit and an external reset input for reliable initialisation and system recovery.
• Low Power Consumption: Designed for energy efficiency with a maximum standby current of just 1μA, making it suitable for battery-powered and low-power designs.
• Wide Operating Range: Functions across a broad supply voltage from 1.8V to 5.5V and an extended temperature range from -40°C to +125°C, ideal for demanding industrial environments.

Housed in a compact SSOP-20 package, this I/O expander is a versatile and reliable solution for adding digital I/O capacity to embedded systems.