Patent ID: 9515603
Filing Date: 2016-12-06
CPC Classification: H03B,H03L

Claim Text:
1. A crystal oscillator start-up circuit, comprising: a crystal oscillation unit configured to generate an output signal on a first node of the crystal oscillation unit according to an impedance characteristic of a crystal oscillator; a converter configured to convert the output signal to a voltage signal corresponding to the impedance characteristic of the crystal oscillator and to output the voltage signal as a control signal, wherein the converter comprises: an external oscillator configured to generate an oscillation signal, a frequency of the oscillation signal being based on the control signal, and wherein the external oscillator configured to output the oscillation signal to a second node of the crystal oscillation unit, wherein the frequency of the oscillation signal is adjusted by the control signal to approach a resonance frequency of the crystal oscillator to bring a frequency of the output signal on the first node close to the resonance frequency of the crystal oscillator.