The influence of source impedance in electrical characterization of Solid state lighting sources

This paper investigates the impact of source impedance in electrical characterization of solid state lighting products. A typical current spectrum is given and a model is used to show the significant influence brought about by variable source impedance. In practice, such changes in source impedance are inevitable for measurements done in different locations. A method is proposed to eliminate this impact by inserting a source impedance stabilization network between equipment under test and power supply. It is proved that this method guarantees less than 0.02 % variation in the measurement results which is acceptable for performance evaluation of SSL products.