Patent ID: 7982522

Claim:
A ringing reduction circuit provided inside a semiconductor integrated circuit that includes an output buffer circuit and an output signal line for transmitting an output signal of the output buffer to a load outside the semiconductor integrated circuit, the ringing reduction circuit comprising: a switching element inserted between the output signal line and a high-potential power line or a low-potential power line for supplying a power supply voltage to the output buffer circuit; and a ringing detector that outputs a signal for turning on the switching element when ringing occurs in the output signal and the output signal exceeds a reference level in a positive or negative direction, wherein the ringing detector comprises a comparator for detecting that the output signal exceeds the reference level in the positive or negative direction by comparing a level of the high-potential power line or the low-potential power line with a level of a power line that is different from the high-potential power line and the low-potential power line and is not part of a path of a switching current flowing through the output buffer circuit.