The road is long but inevitable: Talking about the road to 42V automotive electronics

There are many reasons to switch to 42V automotive electrical systems. However, the actual implementation of 42V is limited by economic and technical challenges. Engineers continue to optimize the performance of 14V systems while solving the challenges of 42V systems. But in the future, it seems that the growth of automotive electrical systems will favor 42V systems. At that time, manufacturers will have to continue to provide improved and innovative products for current 14V systems while being able to support future 42V systems. This article will discuss the implementation of 42V and delve into future development trends.

The road is long but inevitable

What is the progress of 42V automotive electrical systems? The more powerful 42V standard has run into trouble with the initial predictions of rapid implementation, and no one is predicting rapid adoption anytime soon. In fact, some experts predict that the transition will not happen at all. Optimization of 14V architectures and components, including distributed power network stability techniques, have extended the life of 14V systems. However, at some point in the future, system performance factors will force automakers to finally accept the transition to 42V. Successful suppliers of electronic and electrical components will be well positioned to support this irreversible transition along the way. However, while developing how to cost-effectively solve the various challenges presented by the 42V power network, manufacturers will continue to optimize their current products for 14V systems.

Factors driving conversion

As automotive electronics and electrical components continue to evolve, manufacturers face unprecedented challenges in ensuring effective power delivery. Driven by new comfort and safety features, improved fuel efficiency, reduced emissions, and improved driving performance, the rate of increase in automotive electronic content has greatly accelerated since the last decade, and this situation will continue in the next 10 to 15 years. The realization of the electrical functions and performance of some representative power loads in the electrical system requires some kind of improvement in the distribution and management of automotive power. These new electronic systems provide the fundamental driving force for the transition to 42V automotive electronic systems.

The benefits of adopting a higher supply voltage electrical system include:

1. Able to meet the power requirements of some accessories that the 14V system cannot meet;

2. Improved power management capabilities and system stability;

3. Reduced current;

4. Reduce the number, volume and cost by reducing electrical wiring and components and replacing mechanical systems with electrical systems;

5. Increased fuel efficiency;

6. Reduced the NVH of the vehicle.

On the surface, so many benefits seem to provide sufficient reasons for the adoption of the 42V standard. However, the reality is that engineering improvements and component capabilities have delayed the life of 14V systems. From improvements in electrical component efficiency, changes in architecture to system-level functional integration, and distribution methods for power network stability, manufacturers have delayed the large-scale transition to a completely different new standard. In addition, there are many economic and technical reasons that prevent the actual implementation of 42V systems. These reasons include:

1. The cost of replacing component technologies and architectures that have been optimized for 14V systems;

2. Long-term stability issues caused by higher voltage and power levels;

3. Potential safety issues;

4. Sparking problems between components and wires.

Figure 1: Comparison of the advantages of 42V system and 12V system.

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The road ahead for 42V

Based on our observations, the outcome of 42V systems is not a simple matter of one or two factors. It is a complex mix of factors that must be balanced when making decisions. It is true that in some areas, the 14V power network cannot meet the power performance required as the electronic content of automobiles continues to increase. There are indeed many reasons to switch to 42V systems, ranging from improved fuel efficiency and radiation improvements to the ability to achieve higher safety performance. However, there are also many reasons to maintain the status quo. The lack of a clear dividing line in the transition to 42V requires some resources to be allocated to the development of new technologies. Automotive electronics suppliers must also continue to develop and improve products based on traditional 14V systems. At the same time, they must also keep a close eye on the development of technologies and products that will support 42V systems in the future.

To understand where the problem lies and what the future holds, let's look at the pros and cons mentioned above. First, it is certain that there are no unsolvable technical problems for 42V systems. The real problem is cost, which is partly caused by the comparison with 14V systems. For example, 42V systems can provide batteries with life comparable to 12V systems, but require more expensive technology, such as lithium batteries or nickel metal hydride batteries to achieve this. Sparking and corrosion problems can also be solved by adding battery disconnect switches and sealed connectors, which means that it only adds some cost.

Suppliers will continue to improve technology to reduce the cost of solving the above problems. At the same time, the application of automotive electronic and electrical systems will continue to grow. As the relative cost of 42V systems decreases and the electronic content of automobiles increases, the adoption rate of 42V systems will gain momentum, as shown in Figure 2.

Figure 2: The adoption momentum for 42V systems increases as system costs decrease and automotive electronics content increases.

Challenges facing automotive electronics and electrical suppliers

What does this mean for automotive electronics and electrical component suppliers? We firmly believe that these suppliers will continue to solve the challenges of 42V systems while optimizing 14V systems. This will cost R&D budgets, thus affecting the economy of our time. Therefore, a strategy combining technology R&D and product R&D must be adopted to ensure the most efficient use of limited resources.

For example, Fairchild Semiconductor continues to expand its 30V and 40V low-voltage PowerTrench MOSFETs product line. These designs are designed to optimize efficiency, performance, and board area in 14V system automotive applications such as power steering and hybrid starter/generators, as well as motor- and solenoid driver designs. At the same time, the company continues to develop 75V advanced technology MOSFETs based on similar processes.

Fairchild is also developing a new family of multi-function power products that leverage a broad range of analog and power semiconductor processes and advanced packaging technologies that can be optimized for both 14V and 42V systems.

Conclusion

In the future, as the electronic content of automobiles continues to increase and the relative cost of implementing these systems becomes more reasonable, there will be a continuous and gradual shift to 42V systems. Automotive electronics suppliers must work closely with automakers to better understand the needs of the system. They must continue to invest their R&D budgets in improving and innovating their products that support current 14V systems while building technical capabilities that can be used to support future 42V systems. Over a longer period of time, suppliers must also focus on solving the various challenges brought about by 42V power networks at an acceptable cost.