Patent ID: 9172327
Filing Date: 2015-10-27
Classification: H03B

Abstract:
1. A crystal oscillator circuit, comprising: a power supply; a crystal resonator circuit including an oscillator, generating an oscillation signal having a predetermined oscillation frequency; an inverting amplification circuit, having an amplifier input end, a second control end and an inverting amplifier output end, the amplifier input end being coupled to the crystal resonator circuit and receiving the oscillation signal, wherein an inverting amplifier outputs an inverting amplified output signal; a bias circuit, having a bias circuit input end and a bias circuit output end, wherein the bias circuit output end generates a bias circuit output signal controlled by the bias circuit input end, and the bias circuit output signal is coupled to the second control end of the inverting amplification circuit; and a peak detection circuit configured to compare the oscillation signal from the amplifier input end with a reference signal, generate a compare signal based on the comparison, regulate the compare signal to generate a peak detector output signal, and feed the peak detector output signal into the bias circuit input end; wherein the bias circuit comprises a self-adjusting circuit configured to regulate a voltage applied from the power supply to the second control end of the inverting amplifier.