Normal and shallow emitter ballast cell designs for 600 V IGBTs

Insulated gate bipolar transistors (IGBT) require a good combination of on-state, switching, short-circuit and avalanche withstand characteristics for motor control applications. The second generation of Motorola 600 V IGBTs utilizes an emitter ballast cell design for these applications. Four normal emitter, `U´, `H´, `X´, `K´ cells and two shallow emitter designs, N^-/N⁺, N ⁺/N^-/N⁺ have been compared in terms of the above mentioned four characteristics. Among the normal emitter designs, for similar on-state and switching characteristics, the `H cell´ has the best UIS energy withstand capability, while the `U cell´ has the best short-circuit withstand capability. For similar on-state, switching and short-circuit characteristics, the shallow emitter design, N^-/N⁺ has better UIS energy capability than that of the normal emitter designs