请教DAC SFDR仿真方法

iatb · 发表于 2009-3-31 14:37:51

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! {& O( }+ T- g, R" j) u
(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.7 g: k) k5 x9 f; I  r( G' ]
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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.+ z, G, t3 @6 t
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在用matlab做分析时可以将unsettling or overshoot point取出来，但是实际用仪器测试时能否去除掉呢，毕竟输出是连续变化的，整个输出做fft分析

[ 本帖最后由 iatb 于 2009-3-31 14:39 编辑 ]