| 摘要 |
PURPOSE:To decrease the change in the delay due to the fluctuation of power voltage by operating a CMOS inverter circuit while using a constant current circuit comprising MOSFET as a current source in a semiconductor integrated circuit using insulation gate field effect transistor (TR) MOSFET. CONSTITUTION:Gates comprising a P-channel MOSFET 11 and an N-channel MOSFET 12 are connected together to form an input terminal as a CMOS inverter. Further, a depletion type is used for an N-channel MOSFET 13 and the current I1 flowing to the MOSFET 13 is expressed as I1=(1/2)beta.(VTND)<2> because the source and gate of the MOSFET 13 are both connected to -VSS, where beta is a conductance constant and -VTND is a threshold voltage. That is, the current flowing to the MOSFET 13 is constant independently of the fluctuation of power voltage. Since the CMOS inverter circuit comprising the MOSFETs 11, 12 uses the MOSFET 13 as the constant current source, the response speed, that is, the delay time is constant independently of the power voltage. |
