MICROCHIP 16-Bit I/O Expander, I2C, SOIC-28

The MICROCHIP 16-Bit I/O Expander provides general purpose parallel I/O expansion for I2C bus or SPI applications. It 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, whilst 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 using the Polarity Inversion register, and all registers can be read by the system master. Functionally, the 16-bit I/O port consists of two 8-bit ports (PORTA and PORTB), and the device can be configured to operate in 8-bit or 16-bit modes via IOCON.BANK.

Featuring a high-speed I2C interface, this expander includes three hardware address pins that allow up to eight devices on the bus. It offers configurable interrupt output pins, which can be set as active high, active low, or open drain. The INTA and INTB pins can be configured to operate independently or together, with configurable interrupt sources that trigger on changes from configured register defaults or pin changes.

Key Features

• 16-bit general purpose parallel I/O expansion
• High-speed I2C interface
• Three hardware address pins for multiple device operation
• Configurable interrupt output pins (active high, active low, or open drain)
• Independently or jointly configurable INTA and INTB
• Polarity Inversion register for input port data
• Operating supply voltage range from 1.8V to 5.5V