请ACT30 FAE回复这个问题:

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关注中……………………

R5,C5和C6构成ACT30A的反馈补偿网络,同时也作为ACT30A电源VDD输入端的储能及滤波电容,其值是可以修改的,不影响可靠性.

1. Single Capacitor Compensation500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/53/95251178858944.bmp');}" onmousewheel="return imgzoom(this);">
Vfb = Iq * (1/(S*C1)), where S = 2*π*f
Vfb/Iq = 1/(S*C1)
Vfb/Iq = (1/S) * (1/C1)
Pole at frequency = 0 Hz
Gain = (1/C1)
Therefore, small C1 will get a higher gain and faster transient response but easier to oscillate.
2. Capacitor-Resistor Compensation
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Vfb = Iq * (1/(S*C1) + R1), where S = 2*π*f
Vfb/Iq = 1/(S*C1) + R1
Vfb/Iq = (1+S*R1*C1) / (1/S*C1)
Vfb/Iq = (1/S) * (1/C1) * (1+S*R1*C1)
Pole at frequency = 0 Hz
Gain = (1/C1)
Zero at frequency = 1/(2*π*R1*C1)
Small C1 will get a higher gain and therefore faster transient response but easier to oscillate.
Larger R1 will also get a higher gain and phase lead and therefore faster transient response but easier to oscillate.

高人啊,讲的太好了!

又学到了一点,呵呵----