The converter board system converts 390 V DC to 12 V/21 A, achieving over 96% efficiency. It’s designed for safe use in labs and handles high voltages well.
The high-voltage resonant converter board (HVP-LLC) from NXP Semiconductors, paired with the HVP-KV46F150 controller card, forms a system for a 250-W power supply with a 390 V DC input and a 12 V/21 A output. This setup incorporates GaN low-loss switches and a digitally-controlled synchronous rectifier, achieving efficiencies over 96% across a broad load spectrum. The system comprises the controller card and the main board.
The board set operates with high voltages that pose risks of electrical shock, fire hazards, or personal injury if not properly managed. Use this board with caution and implement safety measures to prevent harm or damage. It is suitable only for individuals familiar with high-voltage electrical systems and should be used exclusively in a laboratory environment.
The high-voltage power stage should be powered by a current-limited laboratory power supply for safe operation. If a non-isolated power supply is used, one must be aware of potential differences in ground potentials between the power stage and the oscilloscope, unless the oscilloscope is floating. It is advised to exercise caution, as both probe grounds and a floating oscilloscope can carry dangerous voltages.
The need to enhance the power density of switched-mode power supplies (SMPS) compels designers to opt for higher switching frequencies. However, this increase in frequency leads to greater switching losses in Pulse Width-Modulated (PWM) converters, reducing overall efficiency. Although higher frequencies allow for smaller passive components, saving space, this benefit is often offset by the need for larger heat sinks or forced cooling systems. As a result, SMPS designers are continually searching for ways to reduce these switching losses. One effective approach to address these issues is the use of resonant converter topologies. Resonant converters incorporate a resonant circuit within the conversion pathway.
The LLC resonant topology offers several benefits over other resonant topologies. Most switched-mode power supplies incorporate a transformer to achieve galvanic isolation or to adjust input/output voltage levels. The inclusion of a transformer in the LLC resonant topology provides additional advantages.
The main board features a range of specifications designed to accommodate various needs. It supports an input voltage of 330-390 V DC and can deliver an output power of up to 250 W. The output voltage is set at 12 V, with a capacity to handle an output current of up to 21 A. It operates at a switching frequency range of 75-300 kHz and incorporates GaN low-loss switches. The board is equipped with passive cooling, a digitally-controlled synchronous rectifier, and reinforced galvanic isolation for enhanced safety. It also includes over-current and over-voltage protection mechanisms. For connectivity and monitoring, the board features an SM-bus interface, a serial interface, and analog sensing for output voltage, output current, and resonant circuit current. Additionally, it supports multiple MCU cards and includes a load switch for step-response tuning.
NXP 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.
