The HEV/EV automobile market has surged in recent years with no sign of slowing down. The automotive customers are striving for more efficient, environmentally friendly modes of transportation and car companies are hearing the call. These automobiles have many complex systems which all need to work together, one of which we’ll discuss in this app note. Every HEV/EV car will have an electric motor, and to drive the motor every HEV/EV car will have an inverter. In order to power this inverter the system needs an isolated, low-EMI, thermally optimized supply for the gate drivers. A previously released TI reference design, TIDA-00199, describes a 24-V fly-buck IGBT supply for traction inverters. The automotive market, however, is moving toward 48-V systems which, compared to 24 V, improves system-wide efficiency, weight and cost. But this comes with new challenges in EMI and thermal performance from the power supply. This app note explains how to convert TIDA-00199 to a 48-V design, how to optimize the layout for EMI and thermal performance, and how to modify the circuit to work with other high power switches including SiC and GaN.