Semiconductor circuit including output buffer circuit and drive circuit for driving output buffer circuit

摘要

PURPOSE: To provide a semiconductor circuit where fluctuations in an output voltage are small, a ringing noise is hardly produced in the case of outputting the voltage via transistor(TR) in source-follower connection and a required drive capability can be obtained while preventing an excess voltage from being applied to components included in a drive circuit driving the TR. CONSTITUTION: The semiconductor circuit is provided with the 1st TR 3 in source follower connection, the drive circuit 1 that is connected to a gate N1 of the 1st TR 3 and applies a 1st level to the gate N1 in response to an input signal Data T, and a charge pump 2 that is connected to the gate N1 and applies a 2nd level higher than the 1st level to the gate N1 in response to the input signal Data T. Furthermore, the semiconductor circuit may be provided with an internal step-down power supply that steps down the power supply voltage and stabilizes the voltage in addition to the components above. In this case, the internal step-down power supply applies a voltage to the drive circuit 1.