A new control method using JFET for an off-line flyback converter with low stand-by power consumption

To reduce stand-by power consumption in an off-line flyback converter, a number of control methods are used. This paper reviews the conventional method to reduce stand-by power in the off-line flyback converter. A new control method is proposed to reduce power consumption in an input filter part using a junction field effect transistor with maximum sampling period. The proposed control method has been implemented in 0.5μm BCDMOS technology. The validity of the proposed control method is verified by a prototype off-line flyback converter.