The invention discloses a switch
voltage-stabilizing circuit which can regulate
switching frequency as well as current peak, has high efficiency and has no audio-
frequency noise generated in a state of
light load, and method thereof. The switch
voltage-stabilizing circuit comprises an
energy storage component capable of storing energy; a switch electrically coupled to the
energy storage component, wherein the
energy storage component can store energy when the switch is on, and the energy stored in the energy storage component is transmitted to a load when the switch is off; a
control circuit electrically coupled to the switch, wherein the
control circuit compares current flowing through the switch with a
current threshold, when the current flowing through the switch is more than the
current threshold, the switch is off, and the
control circuit determines on and
off time of the switch according to the load of the switch
voltage-stabilizing circuit, when the load becomes big, the on and
off time of the switch is reduced, and when the load becomes small, the on and
off time of the switch is increased. The
current threshold is constant when the circuit has no
light load and becomes low with the load reduced when the circuit has
light load.