Abstract: An oscillation control circuit is offered which can improve the startability of an oscillator circuit operating at high frequencies and at a low power-supply voltage. When the oscillation potential of the oscillation signal is between the inversion potential (1.2 volts) of a CMOS inverter IV1 and the inversion potential (1.8 volts) of a CMOS inverter IV2, the logical output value of a CMOS Schmitt inverter SI1 is 1. The output of a CMOS inverter formed by MOS transistors T32 and T33 is shorted out via a MOS transistor T34. Its logical output value is kept at 1. When the inversion potential of the CMOS inverter IV1 or the inversion potential of the CMOS inverter IV2 is exceeded, if the input voltage to the CMOS Schmitt trigger SI1 increases above its inversion potential (1.8 volts), the logical output value assumes a value of 0. The CMOS inverter formed by the MOS transistors T12 and T13 is first set into operation. The oscillation signal is inverted, setting a circuit LA at a later stage into operation.

Abstract: An oscillator circuit adapted for a piezoelectric oscillator which has a weak oscillation output for generating high frequencies is provided. The speed of operation of the oscillator circuit is increased. An integrated circuit for such an oscillator circuit is also provided. The oscillator circuit has an amplifier portion consisting of CMOS inverters connected in cascade. MOS transistors forming the CMOS inverters have channel widths that decrease successively from the first stage to the last stage to improve the amplification factor of the amplifier portion at high frequencies. This makes it possible to amplify weak oscillation output from the quartz oscillator (XL). A filter circuit produces a peak of negative resistance at a frequency higher than conventional. This permit oscillation operation at higher frequencies.

Abstract: An oscillator circuit adapted for a piezoelectric oscillator which has a weak oscillation output for generating high frequencies is provided. The speed of operation of the oscillator circuit is increased. An integrated circuit for such an oscillator circuit is also provided. The oscillator circuit has an amplifier portion consisting of CMOS inverters connected in cascade. MOS transistors forming the CMOS inverters have channel widths that decrease successively from the first stage to the last stage to improve the amplification factor of the amplifier portion at high frequencies. This makes it possible to amplify weak oscillation output from the quartz oscillator (XL). A filter circuit produces a peak of negative resistance at a frequency higher than conventional. This permit oscillation operation at higher frequencies.

Abstract: An oscillation control circuit is offered which can improve the startability of an oscillator circuit operating at high frequencies and at a low power-supply voltage. When the oscillation potential of the oscillation signal is between the inversion potential (1.2 volts) of a CMOS inverter IV1 and the inversion potential (1.8 volts) of a CMOS inverter IV2, the logical output value of a CMOS Schmitt inverter SI1 is 1. The output of a CMOS inverter formed by MOS transistors T32 and T33 is shorted out via a MOS transistor T34. Its logical output value is kept at 1. When the inversion potential of the CMOS inverter IV1 or the inversion potential of the CMOS inverter IV2 is exceeded, if the input voltage to the CMOS Schmitt trigger SI1 increases above its inversion potential (1.8 volts), the logical output value assumes a value of 0. The CMOS inverter formed by the MOS transistors T12 and T13 is first set into operation. The oscillation signal is inverted, setting a circuit LA at a later stage into operation.