Microchip I/O Expander SPI 18-Pin QFN, MCP23S18T-E/MJ

The Microchip 6 bit 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. 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.

16 bit remote bidirectional I/O port
25 mA sink
400 mA total current out
Low standby current as low as 1 μA
High speed I2C™ interface up to 3.4MHz