Delayed-locked loop with fine and coarse control using cascaded phase interpolator and variable delay circuit
    4.
    发明授权
    Delayed-locked loop with fine and coarse control using cascaded phase interpolator and variable delay circuit 有权
    使用级联相位内插器和可变延迟电路的精细和粗略控制的延迟锁定环路

    公开(公告)号:US07046058B1

    公开(公告)日:2006-05-16

    申请号:US10671305

    申请日:2003-09-24

    CPC classification number: H03L7/0814 H03L7/0818

    Abstract: A delay-locked loop (DLL) circuit includes a phase interpolator circuit and variable delay circuit coupled in cascade and operative to generate an output clock signal that is delayed with respect to a reference clock signal responsive to respective first and second control signals applied to the phase interpolator and the variable delay circuit. The DLL circuit further includes a phase control circuit that generates the first and second control signals responsive to the output clock signal and the reference clock signal. The variable delay circuit may provide a coarser resolution than the phase interpolator circuit, for example, the variable delay circuit may include a tapped delay chain circuit configured to provide step changes in delay responsive to the second control signal. The phase control circuit may be operative to cause the phase interpolator circuit to shift from one extreme of a delay range thereof towards another extreme of the delay range concurrent with a step change in delay through the variable delay circuit to thereby limit overcompensation.

    Abstract translation: 延迟锁定环路(DLL)电路包括相位内插器电路和可变延迟电路,其可级联耦合并且可操作以产生相对于参考时钟信号延迟的输出时钟信号,所述输出时钟信号响应于施加到所述第一和第二控制信号的相应的第一和第二控制信号 相位内插器和可变延迟电路。 该DLL电路还包括相位控制电路,该相位控制电路根据输出时钟信号和参考时钟信号产生第一和第二控制信号。 可变延迟电路可以提供比相位内插器电路更粗的分辨率,例如,可变延迟电路可以包括被配置为响应于第二控制信号提供延迟的延迟阶跃变化的抽头延迟链电路。 相位控制电路可操作以使相位内插器电路从其延迟范围的一个极端移向延迟范围的另一极端,并通过可变延迟电路与延迟的阶跃变化同步,从而限制过补偿。

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