Ringing preventive circuit, device under test board, pin electronics card, and semiconductor device

A ringing preventive circuit, comprising:

• buffer amplifier having an input terminal and an output terminal;
• a first comparator having a first input terminal connected to said output terminal of said buffer amplifier, a second input terminal provided with a first reference voltage, and an output terminal, for outputting a first control signal from said output terminal in response to a result of comparison between voltages at said first and second input terminals;
• and
• a first current supply circuit having a first terminal connected to a first power source for supplying a first voltage, a second terminal connected to said input terminal of said buffer amplifier, and a control signal input terminal connected to said output terminal of said first comparator, for controlling conduction and non-conduction of a current flowing from said first terminal to said second terminal as a function of said first control signal,
• wherein said first current supply circuit comprises:
• a first voltage drop means having a first terminal connected to said first power source, and a second terminal, and
• a first switch means having a first current electrode connected to said second terminal of said first voltage drop means, a second current electrode connected to said input terminal of said buffer amplifier, and a control electrode connected to said output terminal of said first comparator, for controlling conduction and non-conduction of a current flowing between said first and second current electrodes as a function of said first control signal.