Patent ID: 6133801
Filing Date: 2000-10-17
Classification: H03B,H03L

Abstract:
A crystal oscillation circuit comprising:main oscillation means having a crystal resonator which main oscillation means is controlled by a main oscillation control signal and generates a main oscillator output signal;auxiliary oscillation means for increasing an exciting current of said crystal resonator to assist a start of oscillation of said main oscillation means when enabled by a start signal, said auxiliary oscillation means comprising a first switch element, an amplifying element and a second switch element within a series circuit; andcontrol means for generating said start signal to temporarily couple said auxiliary oscillation means in parallel with said main oscillation means at the time said main oscillation means is enabled in order to increase said exciting current of said crystal resonator for a predetermined duration of time defined by said start signal and corresponding to the crystal resonator high-impedance state,wherein said control means comprises a monostable multivibrator circuit which is triggered by said main oscillation control signal to output said start signal to said auxiliary oscillation means until the oscillation becomes stable so said auxiliary oscillation means provides a current to the main oscillation means having a predetermined time width.