Resonant Transformer for Inductor-Inductor-Capacitor (LLC) applications

Vishay Resonant Transformer / Inductor Saves Space & Simplifies PCB Layouts in LLC Applications

Integrated Resonant Transformer Features Fully Tunable Magnetizing & Leakage Inductance, Minimal Parasitic Variation, & Excellent Heat Dissipation Performance

Vishay Intertechnology introduced a new resonant transformer for inductor-inductor-capacitor (LLC) applications that features both the transformer and an integrated inductor in a single package. Designed to save PCB space while simplifying layouts and reducing component mounting requirements, the 5.5 kW Vishay Custom Magnetics MRTI5R5EZ offers fully tunable magnetizing and leakage inductance with minimal parasitic variation.

Vishay’ Resonant Transformer

The device is the first transformer of its kind to utilize a second middle transformer leg to complete the resonant inductor portion of the circuit. Other implementations require an additional magnetic core to deliver the same performance. Not only does this unique construction save space, but it also simplifies designs by eliminating the need for interconnects or jumpers from the resonant inductor to the transformer’s winding.

The MRTI5R5EZ will be used in on-board chargers and half- / full-bridge resonant power supply transformers in industrial controls, solar inverters, and military, avionics, and construction equipment. In addition to providing a customizable turns ratio for these applications, the transformer’s losses can be moved from the core to the coil as needed to deliver the best performance and heat dissipation, while its minimal parasitic variation optimizes capacitor selection.

The device features operating frequencies from 100 kHz to 350 kHz, rated power from 4 kW to 6 kW with 400 V to 800 V input voltage, and rated current to 28 A. The isolation voltage rating for the MRTI5R5EZ is 2500 V. The transformer includes a bracket for cold plate mounting with raised bosses, with flush-mount options available. M4 ring terminals are standard for the transformer, with customizable lead lengths and terminal types available, and the device can be provided with a thermal gap pad on the mounting surface.

Samples and production quantities of the MRTI5R5EZ are available now, with lead times of four weeks for samples and 16 to 20 weeks for production quantities.