面向低压高频开关应用的功率JFET的功耗

Power Loss of Power JFET Facing to Low Voltage and High Frequency Switching Application

提出了一种埋氧化物槽栅双极模式功率JFET(BTB-JFET),其面向低压高频开关应用。首次通过仿真对BTB-JFET、常规的槽栅双极模式JFET(TB-JFET)和槽栅MOSFET(T-MOSFET)等20V级的功率开关器件在高频应用时的功率损耗进行了比较。仿真中借鉴现有的高性能T-MOSFET的结构尺寸,并采用了感性负载电路对器件进行静态以及混合模式的电特性仿真,结果表明,常开型BTB-JFET与TB-JFET相比,零偏压时栅漏电容CGD减小25%;当工作频率为1MHz和2MHz时常开型TB-JFET与T-MOSFET相比总功耗分别降低了14%和19%,而常开型BTB-JFET较TB-JFET的总功耗又进一步降低了6%。仿真结果还表明,在不同工作频率下,常闭型JFET的性能都不如T-MOSFET。样管初步测试结果证明,常开型BTB-JFET与TB-JFET相比,零偏压时栅漏电容CGD减小45%,与仿真结果相一致。

A buried-oxide trench-gate bipolar-mode power JFET （BTB-JFET） facing to low voltage and high frequency switching application is presented. Power loss comparison at high frequency among 20V-rated power switching devices, including BTB-JFET, conventional trench-gate bipolar-mode JFET （TB-JFET） and trench-gate MOSFET （T-MOSFET）, is carried out by means of simulation based on static analysis and mixed-mode analysis using an inductive switching circuit for the first time. Simulation results show that the gate-drain capacitance C^D of normally-on BTB-JFET has an improvement up to 25% than that of TB-JFET at zero source-drain bias. Normally-on TB-JFET has at least 14% total power loss improvement at 1MHz and 19% at 2MHz compared to that of the T-MOSFET, while normally-on BTB-JFET can provide 6% more improvement at 1 and 2MHz compared to that of the TB-JFET. Simulation results also show that the normally-off JFET always perform worse than the T-MOSFET at different frequencies. The measurement results of samples still under fabrication show that the C6D of normally-on BTB-JFET has an improvement up to 45% than that of TB-JFET at zero source-drain bias, which accords with simulation.