Junction temperature measurement of alternating current light-emitting-diode by threshold voltage method
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Junction temperature of alternating current light-emitting-diode (AC-LED) has a significant effect on its stable light output and lifetime. The threshold voltage measurement is employed to characterize the junction temperature of AC-LED, due to its excellent merits in high efficiency and accuracy. The threshold voltage is measured when the driving current of an AC-LED rises to a reference on-set value from the zero-crossing node. Based on multiple measurements of threshold voltage at different temperatures, a linear relationship was uncovered between the threshold voltage and the junction temperature of AC-LED with the correlating factor of temperature sensitive parameter (TSP). Thereby, we can calculate the junction temperature with the TSP and threshold voltage once the AC-LED stays at thermal equilibrium state. The accuracy of the proposed junction temperature measurement technique was found to be ±3.2°C for the reference current of 1 mA. It is concluded that the method of threshold voltage is accurate and simple to implement, making it highly suitable for measuring the junction temperature of AC-LED in industry.
Keywordsoptoelectronics junction temperature measurement threshold voltage method alternating current light-emitting-diode (AC-LED)
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- 2.EIA/JEDEC STANDARD Integrated Circuits Thermal Measurement Method- Electrical Test Method (Single Semiconductor Device). 1995Google Scholar
- 9.Neamen D A. Semiconductor Physics and Devices Basic Principles. 3rd ed. New York: McGraw-Hill, 2003Google Scholar
- 10.Poppe A, Siegal B, Farkas G. Issues of thermal testing of AC LEDs. In: Proceedings of 27th Annual IEEE Semiconductor Thermal Measurement and Management Symposium, 2011, 297–303Google Scholar