The specially built-in green functions provide high efficiency at all power levels. At high
power levels the flyback operates in QR mode or DCM with valley detection. At medium
power levels, the flyback controller switches to Frequency Reduction (FR) mode and limits
the peak current to an adjustable minimum value. In low power mode, the PFC switches
off to maintain high efficiency. At very low power levels, when the flyback switching
frequency drops below 25 kHz, the flyback converter switches to burst mode. During the
non-switching phase of burst mode, the internal IC supply current is minimized to further
optimize efficiency. Valley switching is used in all operating modes