Patent ID: 6064272
Filing Date: 2000-05-16
Classification: H03L

Abstract:
A frequency synthesizer comprising:a controlled oscillator having a variable output controlled by an input signal;a frequency divider coupled to receive the output of said controlled oscillator and responsive to said output to provide a frequency divided output signal;an on chip tuning circuit coupled to receive the frequency divided output of said frequency divider, said tuning circuit generating a control signal responsive to the frequency divided output of the frequency divider;a phase compensation circuit coupled to receive the frequency divided output signal from said frequency divider, said phase compensation circuit comprising delay elements responsive to said control signal from said on chip tuning circuit, and said phase compensation circuit responsive to said frequency divided output signal to provide an output which compensates for phase lag of the frequency divided output of said frequency divider; anda phase detector coupled to receive the output of said phase compensation circuit and a reference frequency and to output a signal proportional to the difference in phase between the two inputs to control said controlled oscillator.