PUBLISHER: ResearchInChina | PRODUCT CODE: 1721395
PUBLISHER: ResearchInChina | PRODUCT CODE: 1721395
For a long time, the 48V low-voltage PDN architecture has been dominated by 48V mild hybrids. The electrical topology of 48V mild hybrids is relatively outdated, and Chinese OEMs have not given it sufficient attention, making it difficult to become a major incremental market. In contrast, battery electric vehicles (BEVs) and plug-in hybrids (PHEVs) can use high-voltage batteries to create a 48V low-voltage rail to power the entire E/E system.
Future BEV platforms have become the primary target for OEMs to deploy 48V automotive systems. Driven by Tesla Cybertruck, along with the increasing penetration of high-level autonomous driving and chassis-by-wire, the 48V low-voltage PDN architecture for battery electric vehicles will receive growing attention from OEMs, and the maturity of supply chain will rapidly improve accordingly.
48V supply chain and industry chain are rapidly improving maturity
From the supply chain perspective, the 48V architecture is currently limited by the insufficient maturity of component supply chains. The 48V low-voltage PDN (PDN) architecture is divided into 9 major categories and 20 subcategories, with a preliminary assessment of the development priority and technical maturity of each segmented product.
Automotive chassis system, the preferred direction of 48V layout
The automotive chassis system, including brake-by-wire, active suspension, and electric power steering (EPS), etc. are preferred directions for 48V deployment.
Taking EPS as an example, in recent years, the market share of DP-EPS (dual-pinion type) and R-EPS (rack-assisted type) has been rapidly increasing:
The accelerated penetration of new energy vehicles, along with increased vehicle weight, has raised higher demands for steering assistance.
The rapid adoption of high-level autonomous driving functions has necessitated redundant design and full-power steering in steering systems, driving more vehicle models to adopt DP-EPS or R-EPS systems.
The rise of domestic brands and the increase in mid-to-high-end models have raised expectations for steering performance and driving experience.
EPS products with an output force below 16kN have reached a mature stage of technology in China, but there are no mature EPS products with higher output forces available. Meanwhile, vehicles requiring higher output forces in the market generally rely on hydraulic power steering, which cannot achieve speed-sensitive steering. Compared to electric power steering, hydraulic systems suffer from inferior performance and challenging deployment constraints.
To address this, FAW Hongqi has developed a "redundant parallel-axis electric power steering system (R-EPS) with an output force exceeding 20kN," marking its domestic debut. This system supports L2/L3 autonomous driving functions such as super cruise, automated parking, and lane-keeping, achieving ASIL D functional safety. It has already undergone vehicle validation in one of Hongqi's R&D projects.
The R-EPS incorporates a 48V redundant EPS product developed by Jingwei HiRain, featuring a Type-I layout:
Compact product size, offering greater flexibility in spatial arrangement
Designed to meet 48V requirements, significantly reducing power consumption for improved energy efficiency while remaining backward-compatible with 24V applications
High output torque, with motor torque reaching 10Nm and power up to 1.5kW, meeting high thrust demands for enhanced driving comfort and handling
Redundant safety design, fulfilling the safety requirements of advanced autonomous driving and steer-by-wire systems
High safety level, achieving ASIL D system functional safety, developed in compliance with ISO 26262 processes, with a failure rate <=10 FIT, enabling fail-operational safety requirements
Supports cybersecurity
Supports OTA updates
Since braking and steering require high-power motors, traditional 12V low-voltage system cannot meet the power demands. Xiaomi Auto has adopted a 48V architecture for scenarios such as brake-by-wire and steer-by-wire, including:
48V EMB: Xiaomi's intelligent chassis utilizes a 48V low-voltage system, upgrading from the SU7's 12V DPB+ESP10.0 electro-hydraulic braking to a 48V four-wheel fully dry electromechanical braking system.
48V steer-by-wire system: Xiaomi's steer-by-wire system employs a fully redundant design in the hand force simulator and tire actuator, with backup for critical components such as power supply, communication, sensors, main chips, and circuits. This meets ASIL-D functional safety requirements, providing the highest level of safety assurance.
The automotive power supply system is witnessing strong demand for power ICs such as medium-voltage MOSFETs above 80V and 100V GaN FETs
In automotive power supply systems, particularly with ongoing reconstruction of vehicle ECUs, the demand for power ICs is exceptionally high. For current automotive controller hardware design, the power supply system serves as a crucial component, providing electricity to sensors, microcontrollers, actuators, communication modules, and other elements.
48V can function as a vehicle's third voltage rail: even in new energy vehicles equipped with high-voltage systems, a 48V power rail may be introduced to operate medium-power loads (typically between 1kW to 10kW). This development will lead to the widespread adoption of high-voltage (400V/800V) to 48V DC-DC converters.
In 48V systems, the maximum voltage of a fully charged battery pack reaches 60V, rendering traditional low-voltage MOSFETs used in 12V systems obsolete. Consequently, multiple manufacturers have recently introduced medium-voltage MOSFETs rated above 80V specifically for automotive 48V applications.
In April 2024, Infineon launched its first product under the advanced OptiMOS(TM) 7 80V technology-IAUCN08S7N013. This product is designed for automotive DC-DC converters and 48V motor control applications (such as EPS).
In June 2024, onsemi introduced its latest T10 PowerTrench series, also offering 80V medium-voltage MOSFETs for automotive 48V systems. The T10 technology employs a shielded gate trench structure, reducing ringing, overshoot, and noise through its industry-leading soft recovery body diode (Qrr, Trr), achieving a balance between performance and recovery characteristics.
Beyond silicon-based MOSFETs, the GaN industry is also eyeing automotive 48V systems. Several power GaN manufacturers, including EPC, TI, Infineon, and DanXi Technology, have launched 100V GaN FET products targeting 48V automotive applications. Thanks to their high frequency, high efficiency, and compact size, 100V GaN FETs are becoming a key technology for 48V system upgrades and intelligent applications. Major products include:
Innoscience INS2002: A 100V half-bridge driver set for release in 2025, featuring an integrated smart bootstrap switch and adjustable dead time, supporting bidirectional 48V/12V DC-DC conversion for high-frequency applications like motor drives and Class-D audio amplifiers.
Texas Instruments (TI) LMG2100R044 & LMG3100R017: 100V GaN chips with integrated drivers in QFN packaging, compatible with 3.3V-12V logic-level inputs. Suitable for data centers and automotive power systems, they reduce peripheral components while improving power density.
GaN Systems (under Infineon) GS61008T: A 100V/90A silicon-based GaN HEMT supporting top-side cooling, initially used in energy storage and industrial motor drives, with early versions still deployed in some automotive systems.
DanXi Technology DXC6010S1C: A 100V GaN chip (35A/12mΩ) with integrated driver, compatible with traditional silicon controllers. Designed for microinverters and motor drives, it simplifies power path design.
In 12V+48V hybrid electrical architectures, the 48V zonal controller serves as the core energy conversion and management node. UAES's zonal controller solution adopts a 48V/12V compatible design. For the 48V portion, an additional DC/DC stage handles 48V-to-12V power conversion and reverse polarity protection. Short-term implementations may rely on added DC/DC converter chips, but in the long run, adopting 48V PMIC chip technology could eliminate this stage, reducing costs.
Tesla follows a similar approach, using zonal controllers as 48V hubs to distribute power to other vehicle controllers. In its Gen4 zonal controllers, Tesla integrates DC/DC conversion supporting 48V/12V transformation and employs 48V E-fuses for power distribution management.
The standardization of 48V is a critical step toward mass production of 48V systems
Standardization is key to the testing, validation, and production line upgrades for 48V vehicles and components. Currently, voltage requirements and testing for electrical and electronic equipment in road vehicles are primarily based on 12V-24V systems. The first standard for 48V was LV148, which was later replaced by Germany's VDA320. The current standard is ISO 21780:2020. Other relevant standards for electric vehicle safety and testing include ISO 6469 and ISO 21498. In the future, as 48V low-voltage power supply network architectures develop, it is expected that ISO/SAE/GB/LV will introduce more requirements and testing standards for 48V electrical and electronic equipment.
China has recently released the recommended national standard GB/T 45120-2024, "Road vehicles-Supply voltage of 48 V-Electrical requirements and tests." This standard is modified from ISO 21780:2020, which was developed based on the electrical requirements for components in 48V mild hybrid vehicles with a DC 48V power supply. Other DC 48V power supply components may also refer to this standard.
In summary, the standardization and supply chain maturity of 48V systems have significantly accelerated. However, new vehicles still require a 2-3 years cycle for system validation, development, testing, and certification. It is estimated that the inflection point for 48V architecture adoption will occur around 2028.
The industry driver for 48V architecture lies in OEMs' high-performance and differentiated vehicle pre-research planning. The 48V architecture will first be deployed in high-end battery electric vehicles equipped with 800-1000V high-voltage platforms, high-performance powertrains, and advanced autonomous driving features. The industry's momentum primarily depends on the mass production timelines of leading OEMs, such as:
Tesla is prioritizing 48V system trials in premium models like the Cybertruck to gather data and cultivate the supply chain. The upgraded Model S/X is planned to adopt the 48V architecture first in 2025, followed by a gradual rollout across the entire lineup (Model Y will not introduce 48V in 2025). Tesla will use OTA updates to enhance low-voltage system functions in existing vehicles, buying time for hardware iterations.
NIO ET9, based on the NT 3.0 platform, has proactively implemented a redundant 12V and 48V architecture, with the 48V system specifically supporting high-power loads such as the FAS fully active suspension.
Xiaomi Auto is introducing the 48V architecture in applications like brake-by-wire and steer-by-wire systems.
Tesla, NIO, and Xiaomi may gradually adopt the 48V low-voltage PDN architecture between 2025 and 2026. However, due to gaps in the supply chain, they still face a lengthy adoption cycle. Other OEMs' 48V low-voltage PDN platforms remain in the planning stage, with market entry expected to take at least 2-3 years. As new architecture models hit the market, ResearchInChina predicts that by 2030, the adoption of 48V architecture in BEVs will surpass the one-million-unit milestone.