The regulator of reduction voltage includes first transistor, second transistor, filter circuit, capacitance and switch. Drain pole of the first transistor is in use for receiving first DC voltage; grid pole is in use for receiving first control signal, and source pole is coupled to a node. Drain pole of the second transistor is coupled to the node; grid pole is in use for receiving second control signal, and source pole is coupled to a fixed voltage. The filter circuit is connected to the node electrically, and outputs second DC voltage. The switch possesses first end, second end and control end. Switching speed of the switch is higher than the switching speed of the first transistor. When first control signal is turned to enable, first transistor and switch are turned to ON, and capacitance is connected to grid pole and source pole in parallel. |