Integrated Resonant Transformer with Minimal Parasitic Variation Saves Space and Simplifies PCB Layouts in LLC Applications

Vishay Intertechnology, Inc. has introduced a new resonant transformer for inductor-inductor-capacitor (LLC) applications that features both the transformer and an integrated inductor in a single package. The new MRTI5R5EZ resonant transformer offers fully tunable magnetizing and leakage inductance with minimal parasitic variation and is designed to save PCB space while simplifying layouts and reducing component mounting requirements. This device can be used in onboard chargers and half- / full-bridge resonant power supply transformers in industrial controls, solar inverters, and military, avionics, and construction equipment.

This device features operating frequencies from 100kHz to 350kHz, rated power from 4kW to 6kW with 400V to 800V input voltage, and rated current to 28A. The isolation voltage rating for this device is 2500V and it 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.

Features

• 5.5 kW transformer / inductor design for unidirectional LLC applications

• Magnetizing and leakage inductance fully tunable

• Turns ratio can be customized per application

• No interconnects or jumpers needed from resonant inductor to the transformer winding

• Operating frequencies from 100 kHz to 350 kHz

• Designs for 400 V to 800 V inputs

• Bracket included for cold plate mounting with raised bosses (flush mount options available)

• Minimal parasitic variation optimizes capacitor selection

• Built in voltage isolation elevates corona inception

• Designed for cold plate cooling at 65 °C to 75 °C

• Lead lengths and terminal types can be easily customized

• Can be provided with thermal gap pad on mounting surface

• MRTI design: patent pending

Applications

• Charging power supplies for 400 V / 600 V batteries

• Unidirectional LLC converters from 4 kW to 6 kW

• Industrial control, alternative energy, military, avionic, and construction equipment

Availability

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