| 摘要 |
PROBLEM TO BE SOLVED: To provide an ESD protection circuit of small layout area, which does not become a load during normal operation of a differential output buffer.SOLUTION: In an ESD protection circuit, a common mode voltage detection circuit detects the common mode voltage of a differential output signal from a differential output buffer, and outputs a common mode voltage detection signal. An overvoltage detection circuit detects whether the voltage of a common mode voltage detection signal is a common mode voltage at the time of normal operation, or an overvoltage at the time of ESD event occurrence, higher than the common mode voltage at the time of normal operation, and generates a detection signal. When the detection signal indicates that the voltage of a common mode voltage detection signal is overvoltage, an off circuit turns the protected element of the differential output buffer off at the time of ESD event occurrence.SELECTED DRAWING: Figure 1 |
