Estimation of Luminous Flux and Luminous Efficacy of Low-Power SMD LED as a Function of Injection Current and Ambient Temperature

Light-emitting diode (LED) luminous flux and efficacy as a function of temperature and current is important to qualify and optimize the design of an LED system. In this paper, the extension of light output equation was used to estimate luminous flux and efficacy of low-power surface-mounted device LED. The photometric and thermal test reports of LED parameters at a certain range of injection current and ambient temperature were obtained by the combination of T3ster and TeraLED systems. The luminous flux and efficacy as a function of injection current and ambient temperature were predicted. The agreement between the experimental and theoretical results validates the extended equation used in this paper. The optimized operating conditions of LED under test are determined.