Patent ID: 8558630

Claim:
An oscillator circuit comprising: a crystal resonator circuit including a CMOS inverter and a first output and a second output; and an amplifier circuit, wherein the amplifier circuit comprises a differential amplifier circuit including a differential amplifier that amplifies a difference between a first output voltage of the crystal resonator circuit and an output voltage of the CMOS inverter, and the CMOS inverter outputs an inverted voltage of the first voltage to the amplifier circuit from a single input voltage, wherein the first output of the crystal resonator circuit and an input of the CMOS inverter are connected to a negative input terminal of the differential amplifier through a resistor R 1 , and the second output of the crystal resonator circuit is connected to a positive input terminal of the differential amplifier through a resistor R 3 , and wherein some of an output voltage of the differential amplifier is fed back to the negative input terminal through a resistor R 2 , and the positive input terminal of the differential amplifier is grounded through a resistor R 4 .