Semiconductor integrated circuit device

A semiconductor integrated circuit device, comprising:

• a switching transistor that is connected between a voltage output terminal and a voltage input terminal to which a DC voltage is input;
• a terminal to which a control signal is input from outside;
• and
• a control circuit that controls the switching transistor to an on state or an off state based on the control signal,
• wherein the control circuit includes:
• a reference voltage source that generates a reference voltage from the DC voltage which is input to the voltage input terminal;
• a differential amplifier to which the reference voltage and a voltage of the voltage output terminal are directly input, and which outputs a voltage to be applied to a control terminal of the switching transistor;
• and
• a logic circuit that generates a signal to control an operation state of the differential amplifier based on the control signal input to the terminal,
• wherein according to an output signal of the logic circuit, the differential amplifier controls the switching transistor to the on state in response to the control signal being a first logic level, and controls the switching transistor to the off state in response to the control signal being a second logic level, and
• wherein a voltage lowered by the reference voltage from the DC voltage input to the voltage input terminal is output to the voltage output terminal.