The Design And Implementation Of The I-V Curve And Junction Parameters Measure-ment System For Diodes

The diode plays an import role in the electronic industry since it was invented in1946. The detection of the diode’s characteristic parameters has been exploring till today. Among the detection technology, the current-voltage (I-V) method is a very commonly used detection method. It’s used to detect the diode’s reverse saturation current, series resistance, ideality factor, emission coefficient and barrier height. I-V method is only based on a high accurate I-V curve. It’s used quite widespread for its model is simple and easy to be analyzed. It’s hard to acquire a high-precision curve and obtain the parameters automatically for the I-V method.This paper introduces the diode’s parameters, principle and detection method. A system which can be used to test and show the characteristic curve of a diode is showed in the paper. This system is specifically tailored to the production manufac-turers with small batch orders. This system is simple, low cost, high reliability. The core component of the system is ATmega16. The system provides the voltage to the diode with a resistor in series. The voltage of the diode and the resistor can be meas-ured by the Analog to Digital Converter (ADC). Then the current of the diode can be computed from the voltage and value of the resistor by the Ohm’s law, which can provide high precision constant current source to the diode and measure diode’s volt-age. The system gets the I-V points in this way and shows characteristic curves in the GUI. The users can change both the manual and automatic measurement with the keyboard. In this paper, the double threshold RANSAC adaptive filtering method (DRANSAC) is proposed. The system can obtain the junction parameters automati-cally.