应用在FPLL中,Delta-Sigma Modulator的输入是一个恒定的的小数分频值,我们希望得到的输出(未经过LPF)是一个仅由对应小数分频值的直流分量与PLL带宽外的高频分量组成的整数信号序列。信号通过Delta-Sigma Modulator后仍存在一定的周期性,也就会导致量化噪声杂散的剩余,因此可以通过在Delta-Sigma Modulator的最低位加入一...
如果与形状VCO相位噪声相当,这种\Sigma\Delta相位噪声谱的峰值会带来麻烦。 图11.26总结了合成器输出的相位噪声效应。 上述研究表明,除非显著降低PLL带宽,否则阶数高于2的\Sigma\Delta调制器在综合器输出处会产生相当大的相位噪声,这个取舍违背了分数N合成器的大带宽前提。 11.2.5 电荷泵失配的影响 第9章对PFD / CP...
This paper investigates the design of digital Sigma-Delta Modulator (SDM) for fractional-N frequency synthesizer. Characteristics of SDMs are compared through theory analysis and simulation. The curve of maximum-loop-bandwidth vs. maximum-phase-noise is suggested to be a new criterion to the ...
compensationisnecessarytocorrectfortheinstantaneousphaseerror.FractionalNImplementationThismethodisfractionalNaveraging.ItalsoappliestosigmadeltaPLLs,whichwillbediscussedlater.Nowexplainingthephaseerrorisalittlemorecomplicated.ConsiderwhenthePLLfirstdividesby865.Nowitwassupposedtodivideby865.2,thustheresultingcomparison...
Disclosed is a delta-sigma modulated fractional-N PLL frequency synthesizer which performs fractional-N by modulating a divider that divides output frequencies from a voltage controlled oscillator. Fractional part data F from a register is forwarded to a second adder. A first adder adds output from...
1.A High Resolution Sigma-Delta Fractional-N Frequency Synthesizer一种高分辨率∑△小数分频频率合成器 2.Design of Frequency Scanner Based on Delta-Sigma Fractional-N PLL LMX2471基于小数分频数字锁相环LMX2471的扫频仪设计 3.Analyze and Eliminate the Fractional Spur of Σ-ΔModulator Fractional Divider∑...
3) fractional-N frequency synthesizer 小数分频频率合成器 1. All analysis of quantization noise for single-loop Δ-Σ modulator for the fractional-N frequency synthesizer is based on linearization assumptions. 以往对小数分频频率合成器中的Δ-Σ调制器的量化噪声大都建立在线性分析的基础上,这样得出的...
14.Design of Frequency Scanner Based on Delta-Sigma Fractional-N PLL LMX2471基于小数分频数字锁相环LMX2471的扫频仪设计 15.Separates the odd and even scanlines of a video clip.分开奇数和偶数视频片段的扫描行. 16.Analyze and Eliminate the Fractional Spur of Σ-ΔModulator Fractional Divider∑-△调...
4.COMPARISON OF SIGMA-DELTA MODULATOR FOR FRACTIONAL-N PLL FREQUENCY SYNTHESIZER [J], Mao;Xiaojian;Yang;Huazhong;Wang;Hui 5.COMPARISON OF SIGMA-DELTA MODULATOR FOR FRACTIONAL-N PLL FREQUENCY SYNTHESIZER [J], Mao Xiaojian; Yang Huazhong; Wang Hui 因版权原因,仅展示原文概要,查看原文内容请购买 ...
Sigma-Delta modulatorPhase NoisePhase Locked LoopFractional-N Frequency Synthesizerpower has become one of the most important parameter in various communication systems such as optical data links, wireless products, microprocessor ASIC/SOC designs. This paper presents the design and simulation of VLSI ...