With its robust design and flexible control options, this resonant converter is an ideal solution for a variety of applications, including server power supplies, telecom rectifiers, automotive charging systems, and industrial power supplies.
Resonant converters are essential DC-DC converters widely used in various industries, including server, telecom, automotive, and industrial power applications. They are favored for their high efficiency, compact design, and ability to meet evolving industry standards and stringent power density requirements. These qualities make resonant converters an excellent choice for medium to high power applications, where both performance and reliability are critical.
This reference design TIDM-1001 by Texas Instruments (TI) introduces a 500W digitally controlled two-phase interleaved LLC resonant converter. Designed for high power density and efficiency, it utilizes a single C2000™ microcontroller (MCU), specifically the TMS320F280025C, to manage all operational modes and generate precise pulse-width modulation (PWM) signals for the converter’s power electronic switches. A unique feature of this design is its innovative current sharing mechanism, which ensures accurate current balance between the two phases without requiring additional hardware, enhancing efficiency and reliability. In terms of performance, this converter delivers 500W of power, equally distributed as 250W per phase or a full-load current of 42.5A. The design accepts an input voltage range of 370V to 410V DC and provides a stable 12V DC output, with a resonant frequency of 250 kHz and a switching frequency range between 200 kHz and 350 kHz.
It has a peak efficiency of 94.5% and maintains over 90% efficiency for loads above 10% of the rated capacity, making it highly effective even at partial loads.To further enhance functionality, this design features programmable phase shedding, which enables dynamic adjustment based on load conditions to optimize efficiency. It also includes comprehensive fault protection mechanisms, such as phase and output overcurrent protection as well as output overvoltage protection, ensuring safe operation under various conditions. The system is fully supported by C2000 powerSUITE tools, facilitating easier development and customization for users.
The design incorporates several advanced components, beginning with the TMS320F280025C, a powerful 32-bit, floating-point MCU tailored for advanced control applications like digital power, solar inverters, and motor control. The UCD7138 MOSFET driver supports advanced synchronous rectification (SR) control, which minimizes the need for traditional, often lossy current sensing circuits. This driver includes body-diode conduction sensing, allowing for efficient current control. The UCC2752x gate drivers, meanwhile, provide dual-channel, high-speed, low-side drive capability, making them ideal for managing MOSFET and IGBT switches in high-power applications. This configuration enables designers to achieve high power density and reliability in complex power delivery systems, positioning it as a versatile choice for modern power supply needs.
TI has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
