一种测试功率MOSFET热阻的新方法

A New Method for Measuring Thermal Resistance of Power MOSFET

阐述了一种测试功率MOSFET热阻的新方法。该方法选取漏源电流作为温度敏感参数,在相同漏源电压和栅源电压幅度下,当栅源电压条件由直流形式变为脉冲形式时,漏源电流是有差异的,这一差异是由结温的不同造成的。而脉冲栅源电压下环境温度的调整可以用来模拟直流条件下的结温,由此可以测得器件在直流条件下的热阻。该方法具有精度高、实现容易和操作方便等优点,可作为功率MOS器件结温和热阻的有效测试方法。

A new method to measure thermal resistance of power MOSFET was proposed, in which drain current was chosen as temperature-sensitive parameter. For the same drain voltage and gate voltage amplitude, when the condition of the gate voltage changed from DC to pulse, the draincurrent was different, and the difference was caused by different junction temperatures. The junction temperature in DC gate condition could be simulated by modifying ambient temperature in pulse gate condition, which could then be used to measure thermal resistance in DC gate condition. Featuring high accuracy, easy implementation and convenient operation, this technique may serve as an effective method for measuring junction temperature and thermal resistance of power MOSFETs.