A SPICE-based transient thermal-electronic model for LEDs

In this work, a SPICE-based transient thermal-electronic simulation model of LEDs with consideration of transient temperature is developed. A RC network is used to simulate the thermal compact model, which voltage distribution equals to thermal compact model's temperature distribution numerically. Voltage and current dependent current sources are used as sources of heat and light. A non-linear dependent source is used to simulate LED's AC behavior. Thermal model and optical model can be integrated with the LED's electronic model. Iteration processes for calculations of electronic-thermal-optical coupling effects can be carried out by the SPICE solver automatically without convergence problem. A selected type of LEDs is measured in different temperature and current levels to verify the proposed model. It has been found that electronic, thermal and optical parameters have good agreement with testing results. Values of major parameters in the propose model have been extracted.