Currently, electric vehicles are entering their next peak period. Unlike before, the world is now facing increasing pressure to reduce carbon emissions. At the same time, semiconductor innovation and the reduction in the price of electric vehicles are making consumers more inclined to choose electric vehicles.
In 2010, the average price of a battery pack exceeded $1,000 per kilowatt-hour; by 2024, that figure is projected to fall below $100. Furthermore, new electric vehicles will have a range of over 300 miles (480 kilometers) on a single charge, three times that of electric vehicles a decade ago. Due to these trends, up to 30% of new cars are expected to be electric by 2025. However, driving more electric vehicles is not without its challenges.
Challenges of vehicle electrification
As automakers develop more innovative and affordable electric vehicles, the demand for efficient charging stations is growing, further boosting consumer adoption. A standalone DC fast charger can charge an electric vehicle to 80% in just 30 minutes, while slow charging at home can take more than 10 hours. To reduce charging time, large DC charging stations are being deployed densely; however, these standalone charging stations can be expensive to design and consume significant amounts of power in both normal and standby modes. To meet these power demands, engineers are tasked with making the grid and the electronics within the vehicle smaller, more reliable, more efficient, and more affordable.
Semiconductor Innovation in the Electric Vehicle Ecosystem
To achieve optimal vehicle efficiency and faster charging times at higher power levels, a holistic approach is crucial, starting with a comprehensive understanding of the entire system, from power source to load. For rapidly evolving applications such as electric vehicles and hybrid electric vehicles, system components need to be scalable and flexible to accommodate changing high battery voltages, bidirectional charging, and time-to-market. There are two distinct power management objectives—high power density and low electromagnetic interference (EMI)—to improve the efficiency of high-power electric vehicles and DC charging systems within a smaller footprint.
Power density
Gallium nitride (GaN) is becoming synonymous with power density because it switches up to 10 times faster than traditional silicon MOSFETs or even silicon carbide devices. This fast switching is only enabled when the output of the drive source (such as a gate driver) is closely connected to the gate of the GaN FET.
Gallium nitride (GaN) can generate near-perfect square waves with very little ringing. Mechanically, it allows for a 59% reduction in transformer size, significantly decreasing the overall size and weight of electric vehicles and thus extending driving time.
Another advantage of GaN's high-speed switching is its extremely high power conversion efficiency, which ranges from 96% to 98% in traditional high-power systems. These systems would typically require a cooling fan system to eliminate hundreds of watts of wasted heat. Typical GaN systems offer over 99% efficiency—therefore, these systems not only use less energy but also eliminate the need for a cooling system. For electric vehicles and charging stations, minimizing heat and power loss is crucial for reducing charging times.
Low EMI
Packaging is more than just providing a shell for electronic components; it must protect circuitry from harsh conditions and protect users from extremely high voltages. For example, Texas Instruments' (TI) ability to integrate more functionality into a single package is driving higher power density, greater system reliability, and lower overall system cost. One example is TI's UCC14240-Q1 DC-DC bias power module with an integrated transformer, which is replacing large and bulky mechanical transformers in EV systems. The integration of magnetic components into integrated circuits is a result of advancements in both silicon and software that have surpassed those of the traditional transformer industry, which uses iron and copper. TI's integrated isolated bias power module enables smaller primary-to-secondary side capacitance and soft-switching control schemes, eliminating the EMI challenges of traditional transformer designs and thus eliminating the need for large and expensive external EMI mitigation techniques such as external chokes and filters.
Furthermore, if high-power systems like electric vehicles are to improve efficiency by 1% to 2%, engineers will have to redesign the entire system from power supply to load, challenging conventional thinking. For example, the low-power centralized flyback bias power supplies used in many systems today could be redesigned with a smaller, distributed power architecture, where new products integrating EMI mitigation, improved efficiency, and double the power density can truly shine.
Towards the Future
TI Semiconductors is enabling a growing number of electronic devices to be powered in a more efficient, reliable, and economical way than ever before. To maintain leadership in power, engineers need to be able to pack more power into a smaller space at a lower cost. Pushing the boundaries of power management means disrupting current thinking. By further improving system-level efficiency, reliability, and cost, semiconductor innovation will continue to play a vital role in automotive electrification.
