GPIO (General Purpose Input/Output), or Bus Expander, products allow easy serial expansion of I/O through an industry-standard I²C, SMBus™, or SPI™ interface. GPIO products can provide additional control and monitoring when the microcontroller or chipset has insufficient I/O ports, or in systems where serial communication and control from a remote location is advantageous.
All of Maxim's GPIO ports can directly drive LEDs, as each I/O port can sink a minimum of 10mA, with most capable of sinking 20mA or more.
All of Maxim's I²C/SMBus-based products feature an integrated, I²C/SMBus internal timeout to prevent the part from locking up the bus.
Each GPIO port can be individually configured through software as either an input or output. Maxim's GPIO product line includes products with as few as 8 ports and up to 28 ports. Maxim also offers GPIO products with both push-pull and open-drain outputs. The GPIO products come in packages as small as a 3mm x 3mm QFN.
Advantages of GPIO (Port Expanders)
- Lower Power: GPIO has lower power consumption (about 1µA) vs. 100µA operating current for a µC.
- Integrated I²C Slave: GPIO has a built-in I²C slave which works at full speed, even in standby mode.
- Smaller Package: GPIO can fit in the smallest packages, down to a 3mm x 3mm QFN!
- Lower Cost: You do not pay for features that you are not using!
- Faster Time to Market: No extra microcontroller code to write, document, and maintain!
- Flexible Lighting Effects: Multiple high-resolution PWM outputs are built-in.
- Predictable Latency: Short and fixed latency between external event and interrupt.
- Better Lighting: Matched current output provides consistent display brightness.
- Easier Routing: Uses only two wires of I²C bus, or three for SPI.
GPIO Selection Guides