TI中文支持网Part Number:LMX2694-EPOther Parts Discussed in Thread:LMX2594
hi,I want to know harmonic requirements of the reference clock。When the harmonic is better than any index, the PLL output spurious is not affected by the clock power.
Amy Luo：
Hi Jiao he,
We have the following recommendation in LMX2594 EVM user's guide, which is also applied to LMX2694.
In order to get lower jitter, the loop bandwidth is usually design to several hundreds kilo Hz. For example, the EVM loop bandwidth is 430kHz.
So reference clock phase noise below 430kHz offset is important as this noise will pass through the PLL.
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jiao he：
Hi,Amy Luo ,
Does the harmonic performance of the reference clock affect the PLL output spurious?
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Amy Luo：
Yes, harmonics are also a form of noise.
