Designing an isolated I2C Bus interface by using digital isolators

The continuing changes in legislation concerning both the design and use of machinery and equipment require the isolation of almost any type of industrial system or interface. The inter-integrated circuit bus (I²C Bus) is a single-ended, multi-master, two-wire bus; and, while designed only for short-distance I²C communication, it is no exception to isolation requirements. This paper provides a short introduction to I²C Bus operation and then describes how to design an isolated I²C interface by adding only a few external components to a digital capacitive isolator.