Switching mode power supply and switch thereof

A switch comprising:

• a plurality of first transistors;
• and
• a second transistor that is turned on/off by a control signal that is equal to that of the plurality of first transistors and in which a second current corresponding to a first current flowing to the plurality of first transistors flows,
• wherein a ratio of the first current to the second current sequentially changes from a time at which the second transistor is turned on.

A switch comprising:

• a first transistor;
• a plurality of second transistors, having a first node coupled to a first node of the first transistor;
• and
• a first resistor with one terminal coupled to a second node of the first transistor and with the other terminal coupled to a first power source for supplying a first voltage,
• wherein a distance between a second power source for supplying a second voltage to a second node of each of the plurality of second transistors and the second node of each of the plurality of second transistors is not uniform.

A switching mode power supply that generates a driving control signal for controlling operation of a switch according to an output voltage and that converts an input voltage into an output voltage, comprising:

• a first switch that is turned on/off according to the driving control signal;
• a plurality of second switches, each with a first node coupled to a first node of the first switch and that is turned on/off according to the driving control signal;
• a resistor with one node coupled to a second node of the first switch and with the other node coupled to a first power source for supplying the first voltage;
• a detection signal output terminal that outputs a detection signal corresponding to the first current flowing to the resistor;
• and
• a switching controller that receives the detection signal and a third voltage corresponding to a second voltage that is generated at an output terminal according to operation of the first and second switches to generate the driving control signal,
• wherein a ratio of a first current to a second current flowing to the plurality of second switches sequentially changes from a time point at which the first transistor is turned on.