MCP23009 is an 8-bit I/O expander with I²C™Compatible interface operating at speeds of up to 3.4MHz. The MCP23009 is available in 18-pin PDIP (300 mil), 18-pin SOIC (300 mil) and 20-pin SSOP packages.

• 8-bit remote bidirectional I/O port:
  • I/O pins default to input
• Open-drain outputs:
  • 5.5V tolerant
  • 25 mA sink
  • 200 mA total
• Low standby current as low as 1 µA
• High-speed I2C™ interface: 100 kHz, 400 kHz,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
• Configurable interrupt source: Interrupt-on-change from configured defaults or pin change
• Polarity inversion register to configure the polarity of the input port data
• External reset input