Low power dissipation crystal oscillator

Claim 2

A low power dissipation crystal oscillator comprising: an inverter circuit including a P-channel insulated gate field-effect transistor and a N-channel insulated gate field-effect transistor connected in series, a single power supply connected to said inverter circuit, an excitation circuit connected between an output and an input of said inverter circuit, said excitation circuit comprising a crystal resonator and a pair of capacitive loads connected between ground and an input and an output of said crystal resonator, respectively, means for applying different DC bias potentials to the gates of said field-effect transistors, respectively, said means comprising a first resistor of high resistance value connecting the power supply to the gate of said N-channel insulated gate field-effect transistor, and a second resistor of high resistance value connecting the gate of said P-channel insulated field-effect transistor to ground.

Claim 3

A low power dissipation crystal oscillator as defined in claim 1, which further comprises a pair of coupling capacitors connecting said crystal resonator to respective gates of said field-effect transistors.

Claim 4

A low power dissipation crystal oscillator as defined in claim 2, wherein an input signal is supplied to the inverter circuit as a feedback from the output of said excitation circuit, the values of said DC bias potentials being determined so that both field-effect transistors may conduct when no input signal is present, and the following inequality holds: V.sub.GN > V.sub.THN, V.sub.GP < V.sub.D - V.sub.THP, where V gn is the gate voltage of said N-channel field-effect transistor, V gp is the gate voltage of said P-channel field-effect transistor, V thn is the threshold level of said N-channel field-effect transistor, V thp is the threshold level of said P-channel field-effect transistor, and V d is the potential value of said power supply.

Claim 5

A low power dissipation crystal oscillator as defined in claim 3, which further comprises an auto-bias circuit including a diode connected in parallel with each said resistor.

Claim 6

A low power dissipation crystal oscillator as defined in claim 1, wherein an input signal is supplied to the inverter circuit as a feedback from the output of said excitation circuit, each different DC bias potential being respectively applied to each gate of both field-effect transistors in such a manner that only when the input signal reaches in the vicinity of its maximum positive-going swing the threshold level of said N-channel insulated gate field-effect transistor, will said N-channel insulated gate field-effect transistor be conductive, and only when said input signal reaches in the vicinity of its maximum negative-going swing the value obtained by subtracting the threshold level of said P-channel insulated gate field-effect transistor from the power supply voltage, will said P-channel insulated gate field-effect transistor be conductive.

Claim 7

A low power dissipation crystal oscillator comprising: an inverter circuit including a P-channel insulated gate field-effect transistor and a N-channel insulated gate field-effect transistor connected in series, a single power supply connected to said inverter circuit, an excitation circuit connected between an output and an input of said inverter circuit, said excitation circuit comprising a crystal resonator and a pair of capacitive loads connected between ground and an input and an output of said crystal resonator, respectively, means for applying different DC bias potentials to the gates of said field-effect transistors, respectively, said means comprising a first resistor of low resistance value connected between one terminal of said power supply and the gate of said P-channel insulated gate field-effect transistor, a second resistor of high resistance value connected between the gates of each of said field-effect transistors, and a third resistor of low resistance value connected between the gate of said N-channel field-effect transistor and ground.

Claim 8

A low power dissipation crystal oscillator comprising: an inverter circuit including a P-channel insulated gate field-effect transistor and a N-channel insulated gate field-effect transistor connected in series, a single power supply connected to said inverter circuit, an excitation circuit connected between an output and an input of said inverter circuit, said excitation circuit comprising a crystal resonator and a pair of capacitive loads connected between ground and an input and an output of said crystal resonator, respectively, means for applying different DC bias potentials to the gates of said field-effect transistors, respectively, said means comprising a first resistor of low resistance value connected between one terminal of said power supply and the gate of said P-channel insulated gate field-effect transistor, a second resistor of high resistance value connected between the gates of each of said field-effect transistors, and a third resistor of low resistance value connected between the gate of said N-channel field-effect transistor and ground.

Claim 9

A low power dissipation crystal oscillator as defined in claim 6 which further comprises a pair of coupling capacitors connecting said crystal resonator to respective gates of said field-effect transistors.

Claim 10

A low power dissipation crystal oscillator as defined in claim 6, which further comprises a bootstrap capacitor for starting oscillation of the crystal oscillator, said bootstrap capacitor being connected in parallel with said second resistor.

Claim 11

A low power dissipation crystal oscillator comprising: an inverter circuit including a P-channel insulated gate field-effect transistor and a N-channel insulated gate field-effect transistor connected in series, a single power supply connected to said inverter circuit, an excitation circuit connected between an output and an input of said inverter circuit, said excitation circuit comprising a crystal resonator and a pair of capacitive loads connected between ground and an input and an output of said crystal resonator, respectively, means for applying different DC bias potentials to the gates of said field-effect transistors, respectively, said means including a self-bias circuit comprising a pair of diodes wherein one of said diodes is connected at the anode thereof to the output of said inverter circuit and is connected at the cathode thereof to the gate of said P-channel insulated gate field-effect transistor through a first resistor of low resistance value, a second resistor of high resistance value connected between the gates of said field-effect transistors, said inverter circuit further comprising an oscillatory circuit including a bootstrap capacitor for starting oscillation of the crystal oscillator connected in parallel with said second resistor, the other of said diodes being connected at the cathode thereof to the output of said inverter circuit and being connected at the anode thereof to the gate of said N-channel insulated gate field-effect transistor through a third resistor of low resistance value.

Claim 12

A low power dissipation crystal oscillator comprising: an inverter circuit including a P-channel insulated gate field-effect transistor and a N-channel insulated gate field-effect transistor connected in series, a single power supply connected to said inverter circuit, an excitation circuit connected between an output and an input of said inverter circuit, said excitation circuit comprising a crystal resonator and a pair of capacitive loads connected between ground and an input and an output of said crystal resonator, respectively, means for applying different DC bias potentials to the gates of said field-effect transistors, respectively, said means including a self-bias circuit comprising a pair of diodes wherein one of said diodes is connected at the anode thereof to the output of said inverter circuit and is connected at the cathode thereof to the gate of said P-channel insulated gate field-effect transistor through a first resistor of low resistance value, a second resistor of high resistance value connected between the gates of said field-effect transistors, said inverter circuit further comprising an oscillatory circuit including a bootstrap capacitor for starting oscillation of the crystal oscillator connected in parallel with said second resistor, the other of said diodes being connected at the cathode thereof to the output of said inverter circuit and being connected at the anode thereof to the gate of said N-channel insulated gate field-effect transistor through a third resistor of low resistance value.

Claim 13

A low power crystal oscillator as defined in claim 9, wherein an input signal is supplied to the inverter circuit as a feedback from the output of said excitation circuit, each different DC bias potential being respectively applied to each gate of both field-effect transistors in such a manner that only when the input signal goes in the vicinity of its maximum positive-going swing slightly beyond the threshold level of said N-channel insulated gate field-effect transistor, will said N-channel field-effect transistor be conductive, and only when said input signal goes in the vicinity of its maximum negative-going swing slightly beyond the value obtained by subtracting the threshold level of said P-channel insulated gate field-effect transistor from the power supply voltage, will said P-channel insulated gate field-effect transistor be conductive.

Claim 14

A low power dissipation crystal oscillator as defined in claim 10, wherein the frequency of said input signal is the same as the resonance frequency of said crystal resonator, and the amplitude of said input signal is the same as that of the voltage applied to both said field-effect transistors.

Claim 15

A low power dissipation crystal oscillator as defined in claim 11 which further comprises a pair of coupling capacitors connecting said crystal resonator to respective gates of said field-effect transistors.