图3-1所示,是85MHz的增强型锁相环(EPLL)和54MHz的EPLL,在C0的输出/输入比率为1:1,C1的输出/输入比率为2:1,且其bandwidth选项设为20MHz时,所对应的.mif文件,这些文件给出了85MHz和54MHz时,PLL的扫描链的设置值。 图3-1 输入时钟为85MHz和54MHz时的PLL的扫描链位图 图3-1给出的.mif文件是通过Quartus...
作为抖动滤波器,通常假设PLL为缓冲器,并在时钟输出端口上再生输入频率。通常将BANDWIDTH属性设为Low能实现更大的抖动滤波,但会导致PLL的静态偏移增大。 2.5 限制 PLL在VCO工作范围、最小和最大输入频率、占空比、相移等方面有一些限制。 VCO工作范围:详见DS202.Table 74.PLL Specification。 最小和最大输入频率:详见...
PLL-charge pump
The constant loop bandwidth over the above tuning frequency ranges is achieved without modifying low pass filter parameters. The current of charge pump \\(Icp\\) is programmed not only to compensate the variation of voltage-controlled oscillator gain \\(Kvco\\) , but also for adapting to the...
Increasing or decreasing the programmable charge-pump current is the easiest way to compensate for changes in the loop bandwidth caused by the variation in Kv. Q. How do I optimize PLL design for phase noise? A. Use low N-value: Since phase noise is multiplied up from the PFD (reference...
if (Locking_Time_meet_SPEC=1) LoopBandwidth=LoopBandwith*k END Iteration from start point 晕哪埃 以我的經驗PLL的頻寬 << reference frequency15 ~ 20倍,我是穩定度的考量和系統需求 以穩定度的觀點來看, 假如PLL採用的是CP(CHARGE PUMP)的架構,在推導CP公式的時候,我們是用連續的系統去近似一個離散的...
8、应的VCO相位间隙选择(VCO phase tap select, c0-c5)n 快速地可动态调整电荷泵电流(Icp)和环路滤波器组件(包括环路滤波器电阻R和电容C),以满足PLL频带宽度(通带宽度,bandwidth)的要求。这些可用于配置的计数器按照特定顺序组织在PLL的扫描链中。增强型锁相环(EPLL,Enhanced PLL)和快速锁相环(FPLL,Fast PLL...
锁相环 PLL 第16讲 龙骧虎步 Optimizing Loop Bandwidth, 视频播放量 5654、弹幕量 10、点赞数 173、投硬币枚数 140、收藏人数 67、转发人数 14, 视频作者 鳌中堂讲电路, 作者简介 ,相关视频:锁相环 PLL 第1讲 盘古开天 Introduction,锁相环 PLL 第45讲 涅盘重生 Digital
in order to attenuate its high frequency content before it feeds into the loop filter opamp. The reason for doing so is that the opamp has limited bandwidth and can exhibit nonlinear behavior if it is directly driven with the high frequencies that are present in the charge pump output. The ...
A charge pump for use in a Phase Locked Loop/Delay Locked Loop minimizes static phase error through the use of an operational amplifier. The charge pump further includes a pull-up c