SYSTEM AND METHOD FOR ESTIMATING THE JUNCTION TEMPERATURE OF A LIGHT EMITTING DIODE

摘要

A method of estimating the junction temperature of a light emitting diode comprises driving a forward bias current through the diode, the current comprising a square wave which toggles between high and low current values (Ihigh, lIow), the high current value (lh?gh) comprising an LED operation current, and the low current value (IIOW) comprising a non-zero measurement current. The forward bias voltage drop (Vf) is sampled and the forward bias voltage drop (VfIow) is determined at the measurement current (IIOW)- The temperature is derived from the determined forward bias voltage drop.