高功率条件下MOSFET栅电荷特性的测量方法

A Measurement Method for Gate Charge Characteristics of MOSFET Under High Power Condition

提出了一种高功率条件下MOSFET栅电荷特性的有效测量方法。在半桥电路的下管开启过程中,沟道出现高电流和高电压同时存在的情况,产生很高的瞬态功率。对于传统栅电荷测试方案,这不仅要求直流电源具备相当的功率输出,而且会在高功率区产生严重的自热效应,无法得到准确的栅电荷特性曲线。文章基于栅电荷测试的基本物理过程和关系,通过测量大电压-小电流与大电流-小电压下的栅电荷特性,获得了高功率条件下MOSFET的栅电荷特性。结果表明,该方法得到的栅电荷特性曲线及参数值与标准规格书的结果非常接近,具有很好的工业应用价值。

An effective measurement method for gate charge characteristics of MOSFET under high power was proposed.During the turn-on process of the lower transistor in a half-bridge circuit,a large drain current and a high drain-voltage would occur,producing a much high transient power.For the traditional test technique,not only an equal high power is required for the DC source used,but also a serious self-heating effect cannot be eliminated.Both of them lead to inaccurate gate charge curves.In this paper,based on the basic physical process and relationship of gate charge test,the gate charge characteristics of MOSFET under high power were obtained by measuring the characteristics of gate charge under high voltage-small current and high current-small voltage.The results showed that the characteristic curve and the parameters obtained by this proposed method were nearly close to the values given by the standard specification,which had good industrial application value.