Low-Cost Multi-Channel Data Transmission over a Single Plastic Optic Fibre for Isolated Sensing Applications

The growing need for higher efficiency in converter systems and in power electronic systems in general has led to the implementation of more complex and sophisticated control algorithms. Often, the controller unit is separated from the sensors and the data has to be transmitted via an isolated channel. Plastic optical fibers are utilized for this task due to their low cost, high robustness and easy handling. In order to reduce the number of fibers, intensity modulation can be used to transmit multiple signals over a single optical fiber. A recently introduced modulation scheme with an additional intensity level indicating the clock allows a simple clock recovery at the receiver. In this paper, three receiver concepts based on this modulation scheme are presented for medium data rates in the range of 20 - 50 Mbps which is sufficient for most power electronic applications. The low complexity and small footprint of the proposed concepts facilitate the system integration. Furthermore, a more compact system can be designed due to the lower number of necessary fibers and corresponding transmitter and receiver circuits.