Electrothermal Model for Power LEDs Based on the Equivalent Resistance Concept for LED Driver Design

Abstract

An electrothermal LED model for the design and simulation of light-emitting diode (LED) drivers based on the concept of the equivalent resistance is proposed in this article. The main contribution of this work is the integration of the temperature variables as the encapsulation temperature, heatsink temperature, and the ambient temperature in an electrical model based on the equivalent resistance of power LEDs. Therefore, an improved model is achieved by including these temperatures. This is because the LED temperatures are critical variables in the LED performance that could reduce the useful life of the LEDs or may even destroy them. Therefore, these temperatures must be considered in the design of LED drivers. The “equivalent resistance” concept has been previously used in the electrical modeling of power LEDs without considering the temperature variables, and this model was used to achieve fast simulations in LED-driver systems. The proposed model is oriented to the area of electronic engineering and it is recommended for the design and simulation of LED-converter systems. Experimental and simulation results are obtained that demonstrate the performance of the proposed model.