| 摘要 |
PURPOSE:To offset or control the decline of the operating speed of MOSFET by increasing the absolute value of the internal power source voltage, which is formed through a stepdown circuit, by proportionating to the change in the process fluctuation of the MOSFET channel length which comprises an internal circuit. CONSTITUTION:In the reference potential generating circuit VLG of the stepdown circuit VD which is built in a dynamic RAM, etc., a pair of resistance means R1, R2, which divide a reference voltage and feed back VF to the uninverted input terminal (gate of Q24) of an operational amplifier circuit that receives a prescribed constant voltage VR at the inverted input terminal (gate of Q23), are provided. The width of the polysilicon of one of the resistors R2 indicates the same change as the gate length of the MOSFET gate through the process fluctuation. Consequently, the absolute value of the internal power source voltage may be increased by proportionating to the change of the MOSFET channel length of the internal circuit. Thus, the decline of the operating speed of MOSFET is offset, and the high speed of the access time of the dynamic RAM is attained. |
