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8 records (took 0.022 seconds)

    1.
    发明专利
    未知

    公开(公告)号：DE60311851D1

    公开(公告)日：2007-03-29

    申请号：DE60311851

    申请日：2003-12-29

    Applicant: ST MICROELECTRONICS SRL

    Inventor： GRAMEGNA GIUSEPPE

    IPC: H03L7/12 ,  H03L1/02 ,  H03L7/00 ,  H03L7/099 ,  H03L7/10 ,  H03L7/191

    Abstract: A device for calibrating the frequency of an oscillator is described. The oscillator (2) has a first and a second input and generates an output frequency (L*S*fo) as a response to a first voltage signal (Vref) applied at the first input. The calibration device (3) is adapted to generate an output digital signal (WD) applied at said second input of the oscillator (2) for calibrating its output frequency (L*S*fo) and it comprises at least one counter (Ti). The counter (Ti) has a first input frequency (fR/2 ) proportional to a reference frequency (fR) and a second input frequency (S*fo) proportional to the output frequency (L*S*fo) of the oscillator (2). The counter (Ti) counts the time window number (Fi) given by the ratio of the second (S*fo) to the first frequency (fR/2 ) and the device (3) comprises means (6) adapted to compare said counted time window number (Fi) with a prefixed time window number (Bi). The calibration device (3) is adapted to change the value of the frequency calibration digital signal (WD) if said counted time window number (Fi) is different from said prefixed time window number (Bi) and until it is obtained that said counted time window number (Fi) is equal to said prefixed time window number (Bi).

    3.
    发明专利
    未知

    公开(公告)号：DE602004011937D1

    公开(公告)日：2008-04-03

    申请号：DE602004011937

    申请日：2004-09-15

    Applicant: ST MICROELECTRONICS SRL

    Inventor： FILOCAMO BASILIO ,  GRAMEGNA GIUSEPPE

    IPC: H03L7/099 ,  H03L7/10 ,  H03L7/187

    Abstract: A method for calibrating the frequency of an oscillator in a phase-locked loop (PLL) is disclosed. For calibration, the loop is opened upstream the VCO and a fixed control voltage is applied, while the frequency of the VCO is altered in response to a digital control word supplied for band selection. The VCO is (1.) steered to a highest frequency, (2.) to a lowest frequency and (3.) repeatedly to an intermediate frequency dependent upon the previously measured frequencies and the desired target frequency. The resolution of the frequency measurement is increased from step to step.

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