MCP23017-E/SP MCP23017 16-Bit I/O Expander with Serial Interface



The MCP23017 device provides 16-bit, general purpose parallel I/O expansion for I2C bus applications. 

The MCP23017 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 registers can be read by the system master.

The 16-bit I/O port functionally consists of two 8-bit ports (PORTA and PORTB). The MCP23017 can be configured to operate in the 8-bit or 16-bit modes via IOCON.BANK. There are two interrupt pins, INTA and INTB, that can be associated with their respective ports, or can be logically OR’ed together so that both pins will activate if either port causes an interrupt. The interrupt output can be configured to activate under two conditions (mutually exclusive):

1. When any input state differs from its corresponding Input Port register state. This is used to indicate to the system master that an input state has changed.

2. When an input state differs from a preconfigured register value (DEFVAL register).

The Interrupt Capture register captures port values at the time of the interrupt, thereby saving the condition that caused the interrupt. The Power-on Reset (POR) sets the registers to their default values and initializes the device state machine.


  • MCP23017-E/SP

This item features:

  • 16-Bit Remote Bidirectional I/O Port: - I/O pins default to input 
  • High-Speed I2C Interface: - 100 kHz, 400 kHz, 1.7 MHz
  • Three Hardware Address Pins to Allow Up to Eight Devices On the Bus
  • Configurable Interrupt Output Pins: Configurable as active-high, active-low or open-drain
  • INTA and INTB Can Be Configured to Operate Independently or Together


  • New and Authentic Component(s) - Microchip MCP23017E-S/P 16-Bit I/O Expander with Serial Interface.
  • Friendly Note: Be mindful of the many, inexpensive, counterfeits available on the market.

General details:

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