WALDENBURG, GERMANY — Würth Elektronik has published its new reference design for a 6W unipoloar isolated auxiliary power supply for SiC MOSFETs and IGBT Gate Drivers. Release RD002 is currently available for free download, and explains the setup of a 27mm x 14mm x 14mm small board with adjustable output voltage.

The reference design delivers a unipolar output voltage of 15V to 20V at 6W of power and can be used in battery chargers, solar system inverters, AC motors or switch-mode power supplies with SiC MOSFETs, as well as other applications. 

An isolated low-power auxiliary power supply, typically with a flyback, push-pull, or half-bridge topology, provides the gate drive voltage level and power required to turn the SiC transistor on and off, as well as galvanic isolation between the high-voltage and low-voltage sides. Isolation is necessary, not only to meet the relevant safety standards, but also to reduce electrical interference due to coupling between the primary and secondary sides of the converter and hence to enhance EMC and the stability of the gate driver control. The transformer in the auxiliary power supply (WE-750318114) performs this main task. The reference design presents the circuitry and components and shows different layout variants.

“As developers, we don't have to keep reinventing the wheel, and that includes circuit technology,” says Falco Eleazar, Application Engineer at Würth Elektronik eiSos. “Thanks to our reference designs, you save a lot of time and can be sure that the components featured are also reliably available from stock.”

Reference design RD002 is available at www.we-online.com/RD002.