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. These inductors not only offer a higher temperature rating but also come with AECQ200 certification, making them an ideal "automotive-ready" solution for automakers looking to develop next-generation vehicles.

The HA78D series of shielded SDM inductors is engineered to support a wide range of DC/DC converter topologies, such as flyback, multi-output buck, SEPIC (Single-Ended Primary Inductor Converter), and Zeta configurations. Their high leakage inductance makes them particularly suitable for SEPIC applications, where the loosely coupled winding enhances efficiency by minimizing circulating current. This design can reduce ripple current by up to 50% compared to using a single inductor.

Modern vehicles contain over 80 electronic systems, each relying on an ECU (Electronic Control Unit), and every ECU typically requires a DC/DC converter. In 2015, automotive electronics accounted for 40% of the total vehicle cost, highlighting the growing importance of efficient and reliable power conversion solutions. Designing DC/DC converters for automotive applications is now more complex due to the need to meet multiple performance, safety, and environmental requirements. Inductors play a crucial role in ensuring these converters deliver the necessary performance and power delivery capabilities.

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.

These inductors feature a rugged enclosure that ensures high efficiency and excellent current handling capability. They also incorporate a low-loss core, making them well-suited for high-frequency DC/DC converters and VRM/VRD applications. With a wide operating temperature range of -50°C to +155°C and AECQ200 certification, they are ideal for use in demanding environments.

Designed with versatility in mind, the HA78D series is RoHS compliant and can be used in series or parallel configurations. They can also be employed as common-mode chokes for EMI noise reduction. This flexibility allows engineers to tailor their designs to specific application needs.

In the automotive sector, these inductors are ideal for lighting systems, hybrid and electric vehicles, start-stop systems, and electronic power steering. Beyond automotive, they find use in industrial, telecommunications, VRM, and PoL (Point-of-Load) applications.

The HA78D series reflects TT Electronics’ holistic approach to inductor design, delivering products that are feature-rich, safe, efficient, and reliable. The magnetic device design and manufacturing processes fully comply with industry safety standards and meet the stringent quality expectations of the automotive sector. By enabling smaller, lighter components with more robust circuitry, these inductors contribute to enhanced system safety and reduced liability risks.

Based on extensive testing, saturation data, and feedback from major automotive and industrial customers, TT Electronics has consistently demonstrated its reliability and commitment to quality. This proven track record makes the HA78D series a trusted choice for engineers working on critical power conversion systems.

Note: The Single-Ended Primary Inductor Converter (SEPIC) is one of the most commonly 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. Most implementations operate in continuous conduction mode (CCM). Since isolation between the input and output is not required in many automotive LED driver applications, the SEPIC topology is particularly well-suited for this purpose.