Selective Gate Driving in Intelligent Power Modules

Due to practical limitations in the manufacturing of power semiconductor dies, high power modules are composed of several dies in parallel in order to meet the desired load current requirements. With careful attention to the design, modern insulated gate bipolar transistor (IGBT)-based power modules feature relatively balanced current distribution amongst the parallel dies. However, owing to the increased switching speeds of wide bandgap devices, i.e., silicon carbide (SiC), it is challenging to design the package to achieve both low-loss and balanced operation. In this article, a technique is proposed where the individual dies in a multidie power module can be selectively driven by a closely integrated gate buffer. Amongst the benefits achieved by selectively driving the die gates, a profiling of the power loss within the intelligent power module is enabled. Furthermore, a practical technique to estimate the individual die temperatures is presented, and using the same method, the on-state voltage of the power module during load current conduction can be estimated. Finally, it is experimentally demonstrated that the combination of individual junction temperature estimation and the selective gate driving can be used to increase the power density of the power module by better utilizing the component dies.