1. Cyberchuck Automotive Electronics 48V System Background

Since the 1950s, the low-voltage circuits of mainstream passenger cars have been based on a 12 volt architecture, which was actually a standard from 70-80 years ago and has been used until now. Currently, various perception hardware such as radar and cameras require higher computing power, higher power speakers, and more screens. In addition, various electrical devices such as electric adjustment and heating have added a lot of extra burden to the traditional 12 volt automotive power distribution bus. The wiring harness is becoming thicker, and the requirements for weight, cost, and space layout are also increasing. Therefore, increasing the voltage is inevitable. 48V is a recognized direction, and early hybrid vehicles raised the voltage to 48V, but it was not until the Tesla Cybertruck was launched that the 48V system was more widely used.

2. Cyberchuck Automotive Electronics 48V System Advantages

（1）Increasing power load: The 48V system can provide higher power load, enabling the car to achieve more and more power consuming functions, such as automatic driving assistance perception system, computing system, 4G/5G transmission, wire controlled steering, and wire controlled braking, all of which require higher power support. Under the same current conditions, a 48V system can output higher power than a 12V system; When the output power is the same, a 48V system can achieve lower current, thereby reducing power loss.

（2）Improving work efficiency: Compared with traditional systems, the 48V system has higher work efficiency, reduces power loss, and has better durability and safety. The 48V system of Cybertruck increases the voltage by 4 times, reduces the required current to 1/4 of the original, reduces energy loss, and also reduces the heat generated by the wiring harness, which can increase the service life and safety of the wiring harness, while allowing electrical components to respond faster.

（3）Optimizing cost and space: Lower current means lighter cables can be used, reducing cable size and weight, saving costs, providing greater driving space for vehicles, and equipping more batteries. Due to the correlation between current and copper material cost, reducing current can also save a significant amount of copper material. For example, Cybertruck's 48V architecture helped reduce wiring by 77% and copper demand by 50%, thereby reducing overall weight, improving efficiency and revenue, and saving Tesla approximately $10 billion in costs annually

4）Simplify the vehicle structure: The 48V system can make the vehicle structure more concise. For example, Tesla Cybertruck replaces CAN bus with high-speed data bus (Ethernet), which can be connected in a daisy chain manner to most components in legacy systems that require point-to-point wiring operation.

3. Shanghai Leimao is moving towards a 48V system protection solution

Switching to a 48V system is a huge project for the entire vehicle supply chain, which requires the cooperation and execution of various manufacturers. At this voltage level, various vehicle specifications and components need to be redeveloped, including capacitors, power devices, wiring harnesses, wire groups, motors, etc. Safety and reliability must be continuously verified. Shanghai Leimao is a vehicle EMC safety protection solution company that quickly responded to this demand and will provide support in surge protection solutions for 48V voltage systems.

4. Why does the 48V voltage system in cars need surge protection

Mainly based on the following important reasons:

Firstly, the automotive electrical system will face various dynamic changes during operation. For example, at the moment the engine starts, the battery will release a large current, which may cause a sharp fluctuation in voltage and generate a surge.

Secondly, sudden switching of electrical loads in vehicles, such as the start or stop of high-power electrical appliances, can also cause instantaneous changes in current and voltage, leading to surge phenomena.

Furthermore, cars may encounter external electromagnetic interference during operation, such as lightning, electrostatic discharge, etc., which can introduce high-energy surge voltages into the circuit.

In addition, electronic devices and control systems in modern cars are becoming increasingly complex and precise, requiring extremely high voltage stability. Sensitive electronic components in a 48V voltage system, such as various sensors, control modules, etc., may experience performance degradation, malfunction, or even permanent damage if impacted by surge voltage, thereby affecting the overall performance, safety, and reliability of the vehicle.

Finally, with the development of intelligent and electric vehicles, the application of 48V voltage systems is becoming increasingly widespread, and their carrying functions are becoming more and more important. Therefore, effective surge protection measures are needed to ensure the stable operation and long life of the system

Therefore, in order to ensure the normal operation of the 48V voltage system in automobiles, avoid damage to electronic devices, and improve the safety and reliability of automobiles, surge protection is essential

5. Surge Protection Scheme for Automotive DC 48V Voltage System

1）Traditional protection scheme: using MOV+GDT+inductor+TVS

2） Shanghai Leiditech recommends a simplified solution: using low residual voltage and high-power TVS

Schottky and PPTC List

Advantages compared to traditional solutions：

（1）Low cost: The traditional solution used 7 components, while the Lei Mao simplified solution used 3 components, reducing costs。

（2）More durable: Traditional solutions such as GDT and MOV have limited usage and are prone to wear and tear. Small replacements increase maintenance costs。

（3）Advantages of simplified solution: LM1K58CLV surge can pass IEC61000-4-5, GB/T17626.5 8/20 μ s 2KV standards. SM8S58CA

For more information, please contact the sales personnel of Shanghai Leimao or the EMC team.