US Patent 7982553 Clock generator

This invention discloses a clock generator capable of automatically adjusting output clock when process, voltage, or temperature variation occurred. The clock generator comprises a current generator, for generating a first current and a second current according to a control voltage; a oscillator, coupled to the current generator, for generating a clock signal according to the first current; and a voltage adjuster, coupled to the current generator and the oscillator, for adjusting the control voltage according to the clock signal and the second current; wherein, when the signal frequency of the clock signal changed, the voltage adjuster correspondingly adjusts the control voltage so as to adjust the first current.