Patent ID: 8487707
Filing Date: 2013-07-16
Classification: H03L

Abstract:
1. A frequency synthesizer, comprising: a PLL, comprising: a switching unit, for switching the PLL to either an open loop status or a closed loop status, wherein a control signal of the oscillator is substantially constant when the PLL is in the open loop status; a second frequency divider, for dividing a frequency of a reference clock to generate a second frequency-divided signal; a counter, for counting according to the first frequency-divided signal and the second frequency-divided signal to generate a counter value when the PLL is in the open loop status; a comparator, for comparing the counter value with a predetermined value to generate a comparing result; and a determining unit, for adjusting an oscillator frequency of the oscillator according to the comparing result; wherein the predetermined value is 2 wherein the comparator comprises: