High-Voltage and High-Current Id-Vds Measurement Method for Power Transistors Improved by Reducing Self-Heating

Abstract

In this letter, an improved measurement method for power transistors is proposed to obtain drain-current characteristics as a function of drain-source voltage (Id - Vds) in high-voltage and high-current (HVHC) ranges. A simple double pulse test (DPT) is utilized in our previous method. However, the self-heating of the device under test (DUT) is not ignorable in the range of high Id. The improved test circuit is equipped with an additional transistor connected in parallel to DUT in order to prevent the flow of a large current into DUT before the measurement. When a trench-gate type SiC MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) is used as a DUT, the power loss of the DUT decreases by about 80%. The transient thermal analysis shows that the die temperature rise is suppressed by up to 10 °C in about 200 A ranges. The newly obtained Id -Vds characteristics are utilized to model the SiC trench MOSFET. The device model reproduces the measured switching waveforms very accurately.