TT Electronics' Coupled Inductors Perfect for Automotive DC/DC Converter Applications

Photocoupler

TT Electronics has launched the HA78D series of coupled inductors, specifically designed for DC/DC converter applications in the automotive industry. These inductors not only offer a higher temperature rating but are also AECQ200 certified, making them an ideal "automotive-ready" solution to support the development of next-generation vehicles.

The HA78D series consists of shielded SDM inductors that are suitable for various DC/DC configurations, such as flyback, multi-output buck, SEPIC, and Zeta topologies. Their high leakage inductance is particularly beneficial for SEPIC applications, where the loosely coupled winding helps reduce circulating current and lowers ripple current by up to 50% compared to using a single inductor, thereby improving efficiency.

With over 80 electronic systems in modern vehicles, each relying on an ECU (Electronic Control Unit), and each ECU requiring a DC/DC converter, the demand for reliable and efficient power solutions is growing. In 2015, automotive electronics accounted for 40% of total vehicle costs, and designing DC/DC converters that meet all requirements has become increasingly complex. Inductors play a crucial role in ensuring performance, efficiency, and power delivery in these systems.

The HA78D series includes four models: HA78D-L128100MLFTR, HA78D-L128220MLFTR, HA78D-L128330MLFTR, and HA78D-L128470MLFTR. When connected in parallel, they provide rated inductances of 10, 22, 33, and 47 microhenries at 100 kHz, respectively.

Designed with a rugged enclosure, these inductors deliver high efficiency and strong current handling capabilities. They also feature a low-loss core, making them well-suited for high-frequency DC/DC converters and VRM/VRD applications. With an operating temperature range from -50°C to 155°C and AECQ200 certification, they are ideal for use in demanding environments.

These inductors are RoHS compliant and highly versatile, allowing them to be used in series or parallel configurations, or as a common-mode choke for EMI noise reduction. Their flexibility makes them suitable for a wide range of applications, including automotive lighting, hybrid vehicles, start-stop systems, and electronic power steering. Additionally, they are applicable in industrial, telecommunications, VRM, and PoL (Point of Load) systems.

The HA78D series reflects TT Electronics’ holistic approach to inductor design, focusing on creating products that are feature-rich, safe, efficient, and reliable. The resulting magnetic device designs and manufacturing processes fully comply with safety standards and meet the rigorous quality demands of the automotive industry. This allows for smaller, lighter components with more robust circuitry, enhancing system safety and reducing potential liability risks for customers.

Based on extensive experience, saturation data, core loss test results, and feedback from major automotive and industrial suppliers, TT Electronics has consistently proven itself as a trusted and reliable partner in delivering high-quality components.

Note: The Single-Ended Primary Inductor Converter (SEPIC) is one of the most widely used DC/DC topologies in automotive LED drivers. It allows the output voltage to be either higher or lower than the input voltage, combining the characteristics of both buck and boost converters. In most cases, it operates in continuous conduction mode (CCM). Since isolation between the input and output is not required in automotive LED driver applications, the SEPIC topology is an excellent choice for this use case.