Thermal analysis of high power LED packages under the alternating current operation

► We report on both experimental and analytical thermal analysis of AC driven LED packages. ► The variation of R th with the input power can be attributed to the h effect. ► The thermal resistance of AC driven LED can be lower than that from DC mode. In this paper we describe a novel thermal characterization method of GaN-based Light Emitting Diode (LED) package driven under the Alternating Current (AC) mode. The result was compared with the results from the thermal analysis for LED package operated under the Direct Current (DC) condition. Different from the DC condition, the junction temperature rise with the operation time of LED package was exhibited in a band formation. Finite Volume Method (FVM) was utilized to calculate the thermal performance of LED package under the AC condition using the input power extracted from the output current and voltage from the AC power supply. The experimental result was in a good agreement with the simulation data.