BD1CM
:截止到2013年的业界最佳相位噪声PLL LMX2581。
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(2014-08-17 11:12) 
多谢分享！
这个器件之前看过不过没留下什么印象。又看了一下还是挺有趣的，管脚同ADF4351兼容，来者不善啊。相噪指标方面，看手册闭环相噪 100kHz以内比ADF4351改善了大概6～14dB，远端相噪差别不大。不过这也可能是测试时不同的环路滤波参数导致的，VCO本身的相噪差别不大，跟ADF4351相比互有胜出，差别在几个dB以内，基本是差不多的，所以还是得实际用过后才能判断
积分抖动性能，这个是100fs RMS, AFD4351是270fs RMS，所以LMX2581用于ADC采样时钟也是不错的选择。
转一个国外VK logger上的评论供参考：
Interesting.... I was not aware of that device. On close inspection it's specs are extreemly close to the ADF4351 and the biggest surprise being the pinouts and pad layout is identical making it a drop in replacement! The register programming is completely different so it is not 100% compatible.
I have a lot to do with the ADF4350 and 4351 and the specs of that device don't appear to have any standout feature to warrant changing for.
However I might see if I can get a free sample or two and try it on one of my existing boards.... I am not sure how kind TI are with their samples.
The statement of industries lowest phase noise is just marketing BS - the Hittite HMC833 for example has a much better phase noise and covers 25-6000MHz making it the industry leader. However at US$38 a piece it is quite an outlay and the benefits can only be seen in application with LO's for >24GHz and DSN recievers on 8.4GHz which phase noise is critical.
73
Wayne ZL2BKC
