White Paper 48VDC

White Paper 48VDC

The Voltage rises

The idea of a higher vehicle electrical system voltage in automobiles is not new. As early as the 1990s, a 42V consortium was set up. However, due to a lack of standards, this approach was not successful. But now everything is to change.

Electricity used to be minimal in automobiles. They mainly ran mechanically. Electric windows? They didn’t exist. For this manually operated handles were used. Today, a whole host of electrical functions such as seat heating, comfort and assistance systems draw a lot of electricity from the battery. In a 12 V vehicle electrical system, higher and higher currents have to flow. To prevent this on-board network from surrendering, manufacturers are now installing a second, stronger network in the car in parallel – with 48 V direct current.


A fundamental advantage of a 48 VDC vehicle electrical system is the lower loss of energy transmission. This is due to lower currents with identical power which results in a considerable savings potential in the design of the electrical conductor cross-sections. This is reflected positively in the weight of the vast quantities of cables installed in modern vehicles.

The 48 VDC vehicle electrical system also enables economical energy recovery and storage during braking (recuperation). The electric motor acts as a generator. In the case of high torque and/or power requirements, however, this system can also support the combustion engine by operating the electric motor in the reverse direction as an electric motor supplied from the 48 VDC battery. This process is also known as a “booster”. By completely decoupling the combustion engine from the on-board power supply, it can even be switched off completely while the vehicle is in motion. In contrast to conventional idling, no losses occur in the combustion engine during “sailing”. This can result in significant fuel savings.

Reflowable Thermal Switch

RTS is a particularly compact overtemperature protection device for power semiconductors in SMD technology. It was developed to protect highly integrated power electronics from overheating, such as those used in the automotive, medical and many other industries.