FREQUENCY SYNTHESIZER HAVING AGREEMENT INDICATOR DEVICE

摘要

The invention relates to a frequency synthesizer comprising a frequency controlled oscillator 1 by a tuning signal TS, a phase detector 4 and a phase-locked loop circuit 5, 6. / P P A tuning indicator device 7 has a tolerance margin on the phase difference between the tuning frequency signal and the reference frequency signal. The phase detector produces a first PS1 and a second PS2 phase signal respectively advance and phase delay between a FT tuning frequency signal and a reference frequency signal FR. The tuning indicator device comprises delay circuits at the input of AND gates so as to eliminate phase signals PS1 and PS2 of duration less than a given duration, and a register producing a confirmed tuning indication signal 15. for at least two successive periods of the reference frequency FR. / P