It started as Inter IC, then IIC, and is now simply referred to as I2C. Regardless what you call it, the two wire interface has been around for a while but doesn't appear to be going away anytime soon. And why should it? I2C is simple, flexible, and, most importantly, established. Most micro's have the port and an array of sensors and auxiliary modules support the interface as well.
With any standard that has existed for some time, a lot of changes can happen around it. Voltage level is one of those changes. As Vcc's drop, differences in potential on a once common platform will arise. Whether it is the micro that drives the change or a latest and greatest sensor, the mismatch is showing up more and more. Mismatches on a common bus are difficult to address with minimal external component additions.
A new IC has been released to handle exactly this. The FXMA2102 from Fairchild Semiconductor is a level translator specifically for this need. Its open drain technology supports the full I2C protocol and includes bidirectional data exchange. Take a look at the feature set at the link below.
