Measurement of Metallurgical p-n Junction Temperature by Dynamics of Current-Induced Heating and Cooling

The paper describes a method for measuring the temperature of the metallurgical p-n junction related to the direct voltage change at ambient conditions. The method developed can be applied both to LEDs and laser diodes. The authors managed to develop the temperature measurement device operated on the basis of the method considered; it measures the temperature of the metallurgical p-n junction by means of analyzing the dynamics of direct voltage change at pulse heating and cooling. The article describes the device and its operating principle. The device consists of two cascades on operating amplifiers OA1 and OA2, an analog and digital converter (ADC), digital and analog converter (DAC), microcontroller (MC) and a personal computer (PC). The sensitivity of the measurement unit is 2 mV/degrees, the period oftransition values reading is 20 msec.