TDK Corporation has launched the new B43655 and B43656 series aluminum electrolytic capacitors, specifically designed for the DC bus of on-board chargers (OBC) in electric vehicles. Both series are optimized for forced cooling conditions and can meet the increasing high voltage and high current demands of next-generation on-board charging platforms. With a compact design and excellent ripple current handling capabilities, these capacitors are widely used in applications where maximum efficiency and reliability are required in tight spaces.
The B43655 series offers high voltage ratings of 475V and 500V, with capacitance values ranging from 110 µF to 880 µF, meeting the needs of 800V battery architectures in modern electric mobility applications. These components are specifically designed for capacitor bottom heat dissipation and high ripple current density, providing over 3,000 hours of service life at +105°C. The maximum ripple current is 3.29A (+105°C), and the ESR value is as low as 100mΩ, minimizing power loss. The B43656 series has a rated voltage of 450V and can handle up to 4.42A of current at +105°C, meeting the stringent requirements of high-power on-board charger topologies.
Both series comply with AEC-Q200 Rev. E standards and are manufactured using RoHS-compliant materials. The capacitors feature a compact solder pin design with diameters ranging from 22mm to 35mm and lengths from 25mm to 60mm, depending on the capacitance value and voltage rating. With enhanced electrical performance and reliability, the B43655 and B43656 capacitors provide robust, future-proof solutions for electric vehicle on-board chargers.
The new B43655 and B43656 series products will also be integrated into TDK’s web-based AlCap lifetime calculation tool.
Component Selection Path under High Voltage Architecture Evolution
The launch of the 475V and 500V voltage ratings in the B43655 series clearly targets the application requirements of 800V battery architectures. This product layout signals that the technology roadmap for high-voltage electric vehicle platforms has entered the substantial component support phase.
For engineers developing on-board charging systems, this means that when designing DC bus capacitors, they need to reconsider the selection standards for voltage margins. Higher bus voltages place new demands on the capacitor’s voltage rating, surge handling capability, and safety certifications.
Leading passive component manufacturers are standardizing and series-developing high-voltage products, providing technical benchmarks for the industry. This also indicates that power topology designs around 800V architectures will become a key focus for power supply R&D in the coming years.
Redefining Thermal Management Paths and Design Collaboration
The product design is optimized for forced cooling conditions, with an emphasis on heat dissipation specifically developed for the bottom of the capacitors. This reveals a significant shift in thermal management thinking.
Traditionally, aluminum electrolytic capacitors rely on natural convection between the outer casing and the air for heat dissipation, with heat transferred from the core to the outside. The B43655 and B43656 series encourage the design of heat dissipation channels directly into the PCB or heat sink structure, establishing thermal connections through the bottom to the cooling plane, achieving more efficient heat dissipation.
This change directly impacts the mechanical layout of power systems: engineers must reserve thermal paths for the bottom of the capacitors, select appropriate thermal interface materials, and integrate the capacitor's thermal model into the overall system thermal simulation. Thermal management is no longer just a component selection issue but an engineering design phase that requires deep collaboration with system structure.
Moving from Estimation to Precise Simulation in Lifetime Prediction
The new products will be integrated into TDK’s web-based AlCap lifetime calculation tool, allowing engineers to simulate the lifetime during the design phase. Reliability validation of power systems has always been a critical stage in the R&D cycle, and the aging characteristics of capacitors, as key components, are closely related to actual operating conditions.
Traditional selection often relies on lifetime data under standard conditions, which may deviate from real application scenarios. The introduction of the AlCap tool means engineers can input specific parameters such as ripple current, ambient temperature, and cooling conditions to obtain a lifetime prediction tailored to specific applications.
This is especially valuable for on-board charging systems that need to meet the 10-15 year lifespan requirement of the entire vehicle. By simulating and selecting models early in the design phase, engineers can reduce trial-and-error costs during the later testing stages, shifting reliability design from validation to selection.
The 2026 World Power Supply Expo
The 2026 World Power Supply Expo will take place from September 16-18 at the China Import and Export Fair Complex in Guangzhou. With an exhibition area of over 50,000 square meters, the event will bring together the entire power supply industry chain, including power systems, core components, production equipment, and testing technologies.
Capacitors, power semiconductors, and other supporting products, as key components of power systems, are continually driving technological upgrades in applications such as new energy vehicles and integrated solar storage charging solutions.
The expo provides a systematic platform for supply and demand matchmaking in power technology, fostering resource collaboration and information exchange across the industry chain. Against the backdrop of global energy transformation and the deep integration of digital technologies, the power supply industry is evolving from a basic energy conversion carrier to an integrated platform that combines energy efficiency, intelligent control, and environmental sustainability. Every component-level technological breakthrough is reshaping the efficiency boundaries and reliability standards of power systems, providing essential support for the innovative development of industries such as new energy vehicles, smart grids, and data centers.
Source: https://www.tdk-electronics.tdk.com/en/373388/