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Normal Mode Operation
In normal mode operation, if the output is in heavy load,
the controller is switching with maximum frequency
(130kHz or 65kHz) and operated with current-mode
control.
Frequency Foldback Mode Operation
AOZ7503 provides green mode operation to reduce
switching loss and improve system efficiency by
frequency foldback function during light load condition.
When the voltage of FB pin is decreased below VFB-E.
The controller will enter green mode and the switching
frequency starts foldback according to load condition.
The minimum switching frequency will be clamped to
FMIN when the voltage of FB pin is below VFB-D.
Skipping Mode Operation
Under very light load condition, the voltage of FB will be
decreased to a very low level. When the voltage of FB is
dropped below the threshold (VSK-E) that is the
hysteresis voltage of internal PWM comparator, the PWM
signal will be blanked and stop to drive MOSFET. After
the output voltage dropped and FB voltage increased
higher than VSK-D, the PWM signal will be resumed.