DAC的SFDR仿真问题
当然应该包括所有的信息。不但应该包括整个transition过程,一个周期内的取样点还
应该尽可能多一些。大部分的harmonic distortion是上升下降沿的glitch引起的。
谢谢你的回答,我在eetop上看到有几个人都说是取稳定了的数据做fft分析,这里确实有些疑惑。其中一个是
prof3 发表于 2009-3-19 15:26
SFDR simulation for ADC or DAC is a little bit different. Correctly predict SFDR for DAC must follow
(1) Proper # of Pts in FFT and your simulation, basically, you need odd number of cycle of signal and have to keep 2^N ppt FFT. E.g. 10bit DAC, best case is to use 1024 pt. Depending on simulation time, most of case 256 pt can also give us good SDFR prediction.I don't agree above author said that increasing # of cycle have no use. This is because your cycle repeating. If cohence sampling cycle, definitely helps.
(2) Pls take out the unsettling or overshoot point during the transient simulation. That is to say, you must use true settling points for FFT. Otherwise your SDFR is harm
Hopefully it helps
请问有没有关于dac测试相关的规范,或者是较为详细的介绍资料
我觉得是因为最后应用的时候后面是有滤波器的。
如果DAC后面还有S/H电路,可以直接取settle的值,否则应该包括所有的glitch,这样的FFT结果才可信