Part Number:LM25085
VIN 24V,VOUT 12V,Imax:5A.The output voltage ripple is normal under static load, and there is no howling phenomenon; when 0.5A~3A dynamic load is executed, the inductor has obvious whistling.When the RT is set to 100K, 200K, 200K, 300K, there is the phenomenon of inductive howling.I would like to ask how to remove the inductance whistling.
Johnsin Tao:
Hi
动态响应输出波形Vpp过大,可以将输出电容适当放大一点,其次注意Cff也是可以改善应向速度的。
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user6414758:
动态的输出纹波并不是很大,但是抽动态载时,电感会啸叫,请问您知道该怎么处理么?
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Johnsin Tao:
HI 将电感的饱和电流选大一点点看看。
不行的话就调cff.
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user6414758:
电感我尝试过将22uH换成33uH的,CFF我尝试过10pf,1nf,100nf,1uf.均无明显效果
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Johnsin Tao:
Hi
Cff按照datasheet里计算来,可以略大一点点,但是不能太大。
电感主要看饱和电流,感值影响的纹波电流。
将电路放上来看一下?
另外将频率调低一点看看?