Small-signal Thermal-Electrical model for Solid State Lighting system based on Chip-On Board technology

The Solid State Lighting systems have become the best option to replace old lighting technologies. The COB packaging technology is suitable due to its high flexibility during design stages. Nevertheless, the high integration levels increases the number of LED-Chips, in addition electrical power increases, thus temperature rise considerably. Small-signal LED models are limited due to the few technical data from suppliers besides thermal influence. A COB-LED small-signal model was developed in Spice to couple thermal and electrical domains. The thermal domain was modelled by thermal resistances. The resistances were calculated using thermal properties and geometry. Only conduction and convection heat transfer mechanism were considered. Eventually, the model was validated against experimental data.