EMV-Fachtagung 2023

Avoiding high inrush current peaks for reducing conducted emission

Andrea HOFER, Seibersdorf Laboratories
Stefan CECIL, Seibersdorf Laboratories



The Competence Unit High-Performance Vision Systems at the AIT Austrian Institute of Technology is developing a 3D scan system including photometric stereo imaging. This system requires special light sources, which are driven with up to 20 A current pulses, to illuminate the object from different angles.

Corresponding high current levels are required for 300 μs during a period of 10 ms, which are leading to high inrush current peaks at conventional LED drivers. These current peaks often lead to problems in the conducted emission spectrum, which requires well matched electromagnetic inference (EMI) filters on the input side of the LED controller.

During a master thesis conducted at the AIT, a LED controller was developed, which buffers the energy required for high current pulses. The poster is presenting some significant improvements in the conducted emission spectrum, caused by the circuit concept of this LED controller.