分频越大对JITTER影响越严重。不过单纯考虑VCO的噪声的话,如果1.2G和2.4G的输出噪声一样,那么2.4G的分4(20lgN)分频噪声要小些,不过实际上2.4G的输出噪声增加量远远大于1.2G输出的6DB。所以还是选用1.2G的输出,2分频。一般来说,分频越多,在分频器输出端引入的噪声也越多,不过这个量可以忽略不计了。不过它要给...
PLL功率与面积上的差异有很多原因。最常见的原因是抖动性能,虽然其它要求(如输出频率和环路带宽)也有作用。设计人员应主要关注周期抖动(period jitter)以及长期抖动(long-term jitter)。周期抖动是当输出时钟本身作为触发器时而产生的误差。此时,对抖动的测量是在一个输出周期的保持解除时间(hold-off)进行的。换句话说,...
There are four kinds of PLL jitter:1.period jitter2.short term jitter3.long term HTSX 2021-06-24 06:48:21 请问一下phasenoise能整个pll跑完再计算jitter吗? 看了hspice的demo里用.sn命令跑的,然后有个phasenoise计算jitter啥的看着都是模块的。这个能整个pll跑完再计算jitter吗?还是也得分开跑再按照...
设计人员应主要关注周期抖动(period jitter)以及长期抖动(long-term jitter)。周期抖动是当输出时钟本身作为触发器时而产生的误差。此时,对抖动的测量是在一个输出周期的保持解除时间(hold-off)进行的。换句话说,这个抖动是一个时钟周期内的误差(即相位误差)。通常测量周期抖动时要采样大量的输出时钟,可以用峰峰值或rm...
长期抖动(Long-term Jitter):长期抖动率如下图(Long-Term Jitter)定义为一个时钟沿相对于基准周期时钟沿经过一段时间的延时之后,与其理想位置的偏离。此测量可以捕获锁相环低频周期变化(缓慢的,频率很低的)。长期抖动对图形、串行连接通讯系统、打印机和任何光栅扫描操作非常重要。
Accumulated jitter, also known as long term jitter, is the deviation in the time of a given clock edge from when the same edge of an ideal clock occurs. This can be accumulated over many clock cycles, as distinct from period jitter which only considers a single clock cycle or cycle-to-...
This white paper is aimed at system architects and physical implementation leaders working on the design of SoCs. It can be confusing to understand the impact of different jitter sources and how to calculate a jitter budget when specifying a digital syst
period jitter――与理想周期比较的差值; cycle-to-cycle――与前一次比较的差值。 TIE――与理想位置比较的差值; short term 和 long term 没有严格的标准定义,通常以上三个单次或少量次数就被看做是 short term,多次的积累(比如1000次,2000次等)被看做是long term。示波器上给出的jitter分布图,要注明测试和...
The long-term jitter is measured as 460 ps pk-pk. This digital PLL is implemented in 0.18渭m CMOS process using 0.417 mm{sup}2 and consumes 61.0 mW power.Tae-Young OhSeung-Hyun YiSung-Hyun YangByong-Chan LimKuk-Tae HongProceedings of the IEEE 2006 Custom Integrated Circuits Conference: ...
Long-term, or N-cycle, jitter is the measure of how muchthe PLL’s output-clock edge deviates from the position of anideal clock over N cycles, where N is typically thousands ofcycles. In other words, long-term jitter is a measure of the accumulated phase error. You usually measure lon...