In-situ LED junction temperature monitoring using LED as temperature sensor

摘要

LED junction temperature is determined in real time using the LED itself as the temperature sensor for directly measuring the LED junction temperature. In addition, temperature measurements from a silicon diode placed in proximity to the LED are also used to complement the temperature measurements from the LED itself. Arbitration is performed among temperature measurements from the LED and temperature measurements from the silicon diode to determine a temperature of the LED junction. The determined LED junction temperature may be used to make adjustments to the LED drive current. Temperature measurements from the LED are made in real time during actual operation by applying snooping currents to the LED during off-times of the PWM cycles of the LED, without interrupting normal operation of the LED.