The choice device for customers is one that gives more Amps per dollar. Basic knowledge of these two components says that FETs have superior switching capabilities while IGBTs have better conduction capabilities. For high currents the expectations are that a FET would perform better than an IGBT. In other words, the FET gives more current out of an application than an IGBT. At lower frequencies, however, the IGBT will give more current than a FET. This is what the graph, shown here, illustrates. The most important factor in this graph is the cross-over point which is located at around 38 kHz. If the application goes below 38 kHz, the designer gets significantly more current from an IGBT than a FET. Similarly, if the application is above 38 kHz, the current output with the bridge implemented with IGBTs becomes lower while the FET stays more or less constant. In this specific three phase inverter motor drive application the current is determined by the thermal consideration of the case which is about 100°C. This implies that the designer has enough cooling capability implemented in terms of a heat sink.