High Dynamic Current Source for LED Light and Data Transmission Applications

In the field of high power LED and laser drive application there is a growing need for fast switching current sources with stable and reliable output levels as well as reproducible switching shapes in the range of several amps. An additional application is the hidden data transmission possibility with RGB-LEDs in combination with conventional lightning applications. The proposed approach discussed in this paper uses a combined structure of a DC-to-DC converter with some auxiliary switches to fulfill the given requirements: A wide input voltage range, and minimized output current ripple, which reduces the problems with EMC. The necessary switching frequencies of a suitable converter are derived.