DC-DC buck降压不稳定请教

zouyufeng

其实这个问题，很是简单的，知道就是知道，不知道就是不知道，和哈

daroubao

What's the control loop type? Current mode, Voltage mode, or ripple based control?

If you designed this converter using the recommendation design from IC vender, then maybe your board design needs improvement. Normally, at high load or when you turn on and off the power supply, the ground will see larger switching noise which may have effects on your control loop, especially for current mode and ripple based control.

Thanks,

daroubao

try to increase the input capacitor and put it near to the power stage. That may help to minize the switching noise.

china_ic

回复 20# pe123


    看你深有体会的样子，投你一票！

muyu0786

应该是过流保护引入的不稳定吧！你好好看看，工作的时候电感电流有没有超过过流值？OCP有没有触发。

jesseyu

   

这样的不稳定有很多可能的原因。我大致列举几个：

1、5V电源来自什么？稳压源？电池？usb？在你的开关附 ...
batnet 发表于 2009-7-8 13:38

                               
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    对，要看下你得testbench是否将这些寄生参数加上，如果没有就太ideal咯
    如果正确地加入咯计生参数，一般来说仿真跟实际不会差太多的

yucai007

正在做DC 学习中

zouyufeng

回复 22# daroubao


    软启动不就是解决这个问题的？

chiarella

给点图看看吧

losen

补偿电容