Issue link: https://resources.mouser.com/i/1496365
a gate driver, and other peripherals. The motor controller then switches power field-effect transistors (FETs) on and off to provide the motor with current and cause it to turn. Each of these individual stages should be highly efficient, but the power FETs are problematic. The silicon-based power FET that is historically used in these systems suffers from many inherent sources of inefficiency, including conduction losses across the transistor channel (i.e., drain- source on resistance) as well as switching losses that occur when the transistor is transitioning between on and off states. This results in relatively high losses across the transistor, leading to power- inefficient motor control and ultimately to loss of driving range. Another source of loss comes from drift in device parameters (e.g., the threshold voltage) as a result of wear, age, or temperature. Drift leads to inefficient device operation and potentially to device failures; thus, drift poses a safety risk that must be monitored. To sidestep the inherent inefficiencies of silicon, many in the industry are turning to other semiconductor materials and transistor architectures such as insulated-gate bipolar transistors (IGBTs), silicon carbide (SiC), and gallium nitride (GaN). Wide-bandgap (WBG) materials like SiC and GaN inherently provide higher efficiencies owing to faster switching speeds and lower conduction losses. The improved efficiency of these solutions has the compounding benefit of generating less heat, meaning that transistors can be made smaller and occupy less area. The resulting weight savings will have an additional benefit to the driving range. C h a p t e r 4 | D e s i g n i n g f o r E f f i c i e n c y One challenge engineers face is how to select components that increase reliability over the long term." C.J. Berg Senior Solutions Engineer, Shell Recharge 18 7 Experts on Designing Vehicle Electrification Solutions