Implementación de un prototipo de fuente de alimentación de 1200v de baja corriente para pruebas de estrés eléctrico en transistores de potencia.

Abstract

A 1200v low current power supply prototype was implemented for electrical stress tests on power transistors. With the creation of this degree project, the problem of lack of instrumentation dedicated to more common reliability tests was attempted. Among them: High Temperature Reverse Bias (HTRB), current-voltage characterization between drain and source. Being this low consto device, user friendly. The prototype design began with the establishment of technical and functional requirements for electrical stress tests, including: variable voltage up to 1200V, current measurement and output voltage throughout the test, user adjustable current limit, overcurrent and over voltage protection, etc. The prototype is based on the Flyback converter, switched by a PWM signal from a microcontroller that is responsible for maintaining stable output voltage through a closed loop control algorithm. For the interaction with the user, an HMI interface was created in the open source QT-creator software. In addition, it provides the ability to be used in other applications such as I-V characterization. Once the prototype design and implementation process was completed, the calibration and testing stage was carried out, where several electrical stress tests were successfully carried out, with the help of a heat station that keeps the device encapsulated at the temperature maximum according to the manufacturer in order to accelerate the failure mechanisms of the MOSFETs in question. The prototype could be improved with the provision of an uninterruptible power supply (UPS), so that the test is not suspended in the absence of electrical power.