| Abstract |
Bipolar transistors of the new generation with ring emitter structure make possible to operate at high switching frequencies without snubbers. The first modules (SIRET®) in totem pole configuration with high current carrying capacity and blocking ability, with three-stage Darlington configurations and the appropriate diodes in hybrid interconnection assemblies, are now available and, through very short switching times, permit increased equipment efficiencies even at higher switching frequencies. This paper deals with special proposals necessary for ensuring disturbance-free application of these elements. They include the suppression of parasitic oscillations during ultrafast switching, measures for assuring ample dV/dt- stability and the investigation of permissible operating ranges at short-circuit. Special attention is also given on the optimization of the transistor switching speed with due attention to the characteristics of the free-wheeling diode, the thermal resistance conditions and the junction temperature coupling of transistor chip and diode chip. |
