UnitedSiC introduces the SiC JFET series for low-power AC-DC flyback converters

     UnitedSiC announced that it has launched a series of SiC JFET chips suitable for co-packaging with controller ics with built-in low-voltage MOSFETs, resulting in extremely fast, common-source, common-gate based flyback products of 20 to 100W. With an operating voltage range of 650 to 1700V, these constant-on-type SiC JFETs enable simplified start-up schemes with zero standby power consumption and are ideal for large flyback AC-DC application markets, including consumer electronics adapters and auxiliary power supplies.

     Controller IC manufacturers benefit from a smaller chip size with extremely low RDS (ON) and capacitance. When used in conjunction with low-QG low-voltage MOSFETs integrated in controller ics, the on-going JFET helps to meet regulations on power consumption under light and no load.

     SiC JFET has a very strong ability to deal with repeated avalanches and short circuits, making SiC common-source common-gate very robust in practice. The SiC JFET is connected in series to the LV MOSFETs in the control IC, and the source voltage of the normal on-type JFET rises to 12V before the JFET is turned off and the IC starts switching. The current path through the JFET can be used as the starting power supply for the controller IC. After the converter starts working, the auxiliary power supply from the converter transformer is gated in with no further power loss.

     Typical low-power flyback applications include consumer electronics AIDS such as laptop and mobile device chargers (20 to 65 W), other applications include wide-input (up to 1400V) flyback auxiliary power supplies for industrial applications such as motor drives, and high-power lighting applications such as long LED string.

     "With the introduction of these new SiC JFETs, UnitedSiC now has one of the broadest SiC power portfolios in the industry, enabling us to deliver high performance JFETs in both chip and discrete packaging," said Chris Dries, UnitedSiC CEO.