MICROCHIP MCP23S08-E/SO

The MCP23X08 device provides 8-bit, general purpose, parallel I/O expansion for I²C bus or SPI applications. The two devices differ in the number of hardware address pins and the serial interface:

• MCP23008 – I²C interface; three address pins
• MCP23S08 – SPI interface; two address pins

The MCP23X08 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. All registers can be read by the system master.

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.

The hardware address pins are used to determine the device address.

• 8-bit remote bidirectional I/O port - I/O pins default to input
• High-speed I²C interface (MCP23008) - 100 kHz - 400 kHz - 1.7 MHz
• High-speed SPI interface (MCP23S08) - 10 MHz
• Hardware address pins - Three for the MCP23008 to allow up to eight devices on the bus - Two for the MCP23S08 to allow up to four devices using the same chip-select
• Configurable interrupt output pin - 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
• Low standby current: 1 μA (max.)
• Operating voltage: 1.8V to 5.5V @ -40°C to +85°C I²C @ 100 kHz SPI @ 5 MHz - 2.7V to 5.5V @ -40°C to +85°C I²C @ 400 kHz SPI @ 10 MHz - 4.5V to 5.5V @ -40°C to +125°C I²C @ 1.7 kHz SPI @ 10 MHz