| 摘要 |
PURPOSE:To eliminate the fluctuation in pulse width, by constituting a delay circuit of a gate oxide film of an MOS element as a capacitance and of a polysilicon layer on the film as a resistor, keeping the time constant accurate and changing the threshold value of a Schmitt circuit with a power supply voltage. CONSTITUTION:A bootstrap circuit 1 applies a voltage slightly higher than a power supply voltage VDD to a gate of an output load transistor Q2 so as to obtain a high-level voltage V0 being the output close to and slightly higher than the VDD. The delay circuit 2 consists of a capacitor C formed with a gate oxide film and a polysilicon layer formed on the film. The Schmitt circuit 3 turns on and off according to the charging voltage of a CR circuit, and either one of the threshold values of ON/OFF operation is changed in response to the VDD. |
