A study of the internal device dynamics of punch-through and nonpunch-through IGBTs under zero-current switching

The effective use of IGBTs requires a good understanding of their internal device physics. This understanding is essential for the optimal interaction between the IGBTs and their snubber elements. As switching frequencies are pushed to higher values, switching loss reduction becomes an essential part of the design and optimization process. Soft switching techniques (ZVS and ZCS) are widely used for this purpose. This study provides insight into the internal dynamic behavior of IGBTs under zero-current switching. This is accomplished through mixed mode simulation, providing the necessary insight for the improvement of circuit and device performance. In particular, we have analyzed the behavior of the negative current in the nonpunch-through device after the first zero-current crossing and the effect of the turn-off delay on the tail current