48V automotive power system, what kind of connector is needed?

At the end of last year, the delivery of Tesla Cybertruck caused quite a stir in the automotive industry. Its sci-fi appearance and excellent driving performance have become a hot topic. However, as the saying goes, experts know the doorway. For developers, Cybertruck's leapfrogging design is more attractive to them, that is - it is equipped with a 48V power supply architecture for the first time, which completely makes the traditional 12V power supply architecture a "thing of the past", and it is a true "48V pure electric vehicle".

1. Moving towards 48V power systems

The architecture of the automotive power system has been developing along with the growth of the demand for automotive power. The first generation of cars did not have many electrical devices, so there was no need to consider the power system. It was not until 1918 that people installed a 6V power system in the car to ignite the engine. Subsequently, in-vehicle electronic devices gradually emerged, and more and more places "used electricity". So in the 1950s, people upgraded the automotive power system to 12V to support 12V in-vehicle batteries to power lighting, in-vehicle entertainment, electronic control units and other low-power electronic devices. This 12V automotive power architecture has become the standard of the automotive industry and has been used to this day.

With the development of automobile electrification and intelligence , the number of electrical loads on vehicles is increasing, and the power that the automotive power system needs to carry and transmit is also increasing, which requires further upgrading. Therefore, in 2011, Audi, BMW, Daimler, Porsche and Volkswagen and other leading automakers jointly launched a 48V power system and formulated the relevant LV148 standard to meet the growing power demand of on-board electronic and electrical equipment.

Compared with the traditional 12V power system, the benefits of 48V architecture are mainly in three aspects:

First of all, of course, it supports higher power output and can "drive" more power loads. The 12V power rail can support up to 3kW of power output, which is inevitably stretched when driving higher power loads; while the 48V system can support up to 10kW of loads, supporting a greater number and more types of in-vehicle applications.

Secondly, the 48V power system is conducive to improving energy efficiency and meeting increasingly stringent emission standards. This is because the voltage "ceiling" of the 12V system is low, and when transmitting more power, it has to increase the current . High current will also lead to higher power consumption, and it will also bring greater challenges to thermal management in the compact vehicle space; while the 48V system can avoid the high power consumption caused by high current through the "high voltage and low current" mode, and achieve higher efficiency. It is estimated that the 48V power system can reduce the total energy consumption by 30%.

Furthermore, in order to carry higher current (greater power), the 12V power system must use thicker wiring harnesses, which will undoubtedly take up more space and increase the weight of the car, which is not conducive to the control of vehicle cost and energy consumption. However, to transmit the same power, the 48V system requires thinner and lighter cables , which is very beneficial for the optimization of vehicle design.

From the above, it is not difficult to see that whether from the perspective of cost reduction and efficiency improvement, or electrification and intelligence, the 48V power architecture is a better choice and represents the general trend of the future. This is also the reason why Tesla has bet on the 48V system without reservation.

Technical considerations for 2.48V power supply system

However, in reality, the migration from 12V to 48V power systems does not seem to be as fast as imagined. On the one hand, this is determined by the characteristics of the automotive industry. The introduction of any technology in the automotive industry must go through a longer testing and verification process. On the other hand, the economic and feasibility of technology upgrades are also very important. After decades of development, from upstream components to downstream vehicle-mounted equipment, the 12V power system has formed a complete technology ecosystem. If you want to complete the replacement, you must consider the smooth transition of the original R&D and supply chain system.

Therefore, at this stage, the 12V + 48V dual-voltage automotive power system has become the choice of many models, that is, two power systems are provided in parallel in the same vehicle - the 12V system is responsible for driving traditional loads, such as lighting, ignition, infotainment and audio, electric windows and door locks and other low-power applications; while the 48V system supports other higher-power loads, such as active chassis systems, air-conditioning compressors, electric superchargers/turbochargers and regenerative braking , etc.

Of course, whether it is a radical "pure" 48V system (such as Tesla Cybertruck) or a robust dual-voltage automotive power solution, it is necessary to build a complete technical ecosystem around the ultimate goal of 48V power architecture and make careful and forward-looking preparations in all aspects. The development of related automotive connectors is an indispensable part of this.

So, what kind of connector does the 48V automotive power system need? We can make a general summary based on the design requirements:

In terms of performance, the connector must meet the requirements of the 48V technical standard and support higher voltage and power.

As an automotive product, the new connector must also be optimized in terms of reliability and safety to adapt to harsh environment applications and ensure a stable connection.

At the same time, compatibility with existing 12V architecture technologies and products must also be taken into consideration to make the upgrade process as smooth as possible and reduce the additional costs incurred.

Connector for 3.48V power system

Molex's MX150 medium voltage connector was developed to meet the automotive industry's growing demand for 48V power systems.

In terms of performance, the MX150 medium voltage connector has a medium voltage capability of 60V and a current rating of up to 22.0A, which can support the design requirements of 48V automotive power systems. And as the name suggests, the connector uses Molex's proven MX150 connector package size and shell design - compared with traditional USCAR connectors, the MX150 connector system has a smaller package size and provides simple and safe mating operations - this allows developers to upgrade directly from existing MX150 connectors, effectively reducing the wiring engineering costs when upgrading to 48V systems.

In terms of high reliability, the MX150 medium voltage connector adopts a series of optimized designs, including pre-assembled Terminal Position Assurance (TPA) housing, Connector Position Assurance (CPA) option, and protective pad-based sealing features to ensure high-quality and reliable connections in harsh environments.

The MX150 medium voltage connector adopts a 3.50mm pitch integrated shell design and provides a 4- circuit single-row configuration, as well as a 4-, 6-, and 20-circuit double-row configuration. The product portfolio is rich, and Molex also provides a complete system solution based on MX150. Designers can choose compatible male and female connectors and terminals, as well as products with various plating options to meet specific application requirements.

This series of connectors complies with IEC 60664-1 specifications and USCAR-2, USCAR-21 and GMW3191 certifications, so if you are looking for a reliable, rugged and proven connector design that meets both low-voltage and medium-voltage functions in the same form factor and can smoothly upgrade to a 48V power system, the MX150 medium-voltage connector is undoubtedly an ideal solution.

4. Fully empower future cars

The 48V power system can be seen as a microcosm of the future development of automobiles: they will provide more functions and higher energy efficiency, while pursuing the ultimate in miniaturization and cost optimization. Such demands are not only reflected in the 48V system, but also widely affect all aspects of automotive interconnection, especially in some cutting-edge applications. To this end, Molex provides a wealth of solutions to fully enable the interconnection of future cars.

In future cars, infotainment systems are a key area to enhance user experience and provide greater added value. The ever-expanding functional requirements have greatly increased the complexity of the design of device and module interconnection in the in-vehicle infotainment system . On the other hand, while supporting this growth in functionality and complexity, the cost cannot be "out of control", which requires a solution with strong scalability and flexibility. For this reason, Molex's stAK50h unsealed connector system came into being.

The stAK50h connector system uses an industry-proven terminal design and provides unsealed hybrid plugs and sockets that enable both signal and Ethernet connections in a very small space. This means that in the automotive infotainment system, only one stAK50h connector interface can handle both signal and Ethernet connections, rather than two separate connection systems.

Furthermore, the stAK50h connector has a stackable feature that allows developers to easily expand the required solution without the need for expensive custom products.

The stAK50h connector system also offers color-coded housings to avoid mismating and incorrect connections by matching the colors of the plugs and sockets. The stAK50h connector series offers configurations from 12 to 56 ways, supporting a wide range of applications from low current signals (5.0A) to high power (30.0A), suitable for body electronics, safety systems, infotainment systems and other various automotive interconnect applications.