Equivalent Circuit Model of High Power LEDs for VLC Systems

The equivalent circuit model for two commercial high power LEDs for illuminance is proposed and extensive measurements have been carried out to verify the accuracy of the model. In addition, the frequency response of two LEDs in the optical domain can be estimated using the transfer function of electrical equivalent circuit. It is shown that, the electrical parasitics in the chip and packaging introduce significant attenuation beyond a resonance frequcency. Care should be taken when designing high-speed driver and/or equalization circuits for VLC systems.