Staying power in the technical realm, where even a few years can render a product irrelevant, is quite an accomplishment. To be around for over thirty years, such as is the case with the Inter-Integrated Circuit (I2C) bus, attests to its usefulness in a wide range of products. Due to specification upgrades that have introduced faster bus speeds, the availability of a wide variety of commodity parts, and continued expansion of I2C-bus peripheral device types, it remains an excellent choice for rapid system prototyping, straightforward product upgrades, and economical new product development.
The I2C-bus design is a simple two-wire serial interface with clock and data lines that reduces connectivity wiring on printed circuit boards, which brings about an associated reduction in cost and EMI/ESD susceptibility. With multi-master capability, an addressing system that supports uniquely addressable devices, bus speeds up to 5 MHz, and the number of simultaneously connected devices on one bus limited only by the maximum bus capacitance, the I2C-bus delivers a cost-effective way to provide system communication for many consumer product applications.
Because of the long history of the I2C-bus in the marketplace, many devices are available in I2C-bus-compatible versions. These parts incorporate an on-chip I2C-bus interface, allowing them to communicate directly with each other via the I2C-bus, and thereby reducing the load on a system microcontroller. NXP’s I2C-bus offerings include general-purpose circuits such as LCD and LED drivers, remote I/O ports, RAM, EEPROM, and A/D and D/A converters, as well as more application specific devices such as stepper motor controllers, real-time clocks, and temperature sensors. Using these off-the-shelf components, consumer product developers, who often already have a system partitioning that includes intelligent control (e.g., micro-controller), general-purpose circuitry, and application-specific circuitry, can readily switch over to an I2C-bus-based design for rapid prototyping.
I2C-bus-compatible devices maybe also be added or removed from a system without affecting other circuits on the bus. So, a system developed around the I2C-bus easily supports the development of a price-point differentiated product family. Simply develop the basic model and add enhanced features with I2C-bus-compatible peripherals. Or, if an existing product needs a quick update, I2C-bus peripherals such as GPIO port expanders, multiplexers, switches, voltage level translators, and bus buffers extend the reach of the existing microcontroller.
NXP offers I2C-bus-compatible devices to fit a extended range of application requirements, such as low power consumption, high noise immunity, wide voltage supply range, and wide operating temperature range. These features are particularly attractive for portable equipment and battery-backed systems.
Visit the NXP I2C-bus website (http://www.nxp.com/products/interface_and_connectivity/i2c) and discover how your design can benefit from the simple, yet powerful I2C-bus interface.