教你如何直观推导两级ota的次主极点的位置——from JoyShockely

hezudao · 发表于 2013-10-19 06:18:59

本帖最后由 hezudao 于 2013-10-19 06:20 编辑

回复 30# liuqilong8819

读书要先读厚再读薄，所以执果索因不仅没有错，反而是应该倡导的，只不过楼主读的还不够。

Evanpeng · 发表于 2013-10-24 12:45:08

回复 29# feynmancgz
are you kidding me?

For example, you design a product of two stages op-amp. Can you ask the customer not put a large cap in the load? Load side is decided by the customer. what you can design is the internal op-amp.

vdslafe · 发表于 2013-10-24 13:13:07

回复 32# Evanpeng

你说的不全对吧。TI/ADI 的运放，都会说最大电容能多少。我曾经看到过当负载电容太大的时候，adi 的运放震起来了

ericking0 · 发表于 2013-10-24 13:54:06

我倒是觉得这种分析方法其实蛮有用的
看到一个电路，直接看到的就是各种电容和电阻
可以头脑里面进行扫频，AC分析

其实多看看多级运放的传函分析的话，自然就会形成这种思考方法

feynmancgz · 发表于 2013-10-24 14:04:29

回复 32# Evanpeng

Are you kidding me? I am talking about teaching in a class. You are talking about design a product.

feynmancgz · 发表于 2013-10-24 14:13:30

回复 32# Evanpeng

Another funny thing is that if your customer ask you to drive a large capacitor, you will choose this topology ?
So funny......

Evanpeng · 发表于 2013-10-25 00:19:06

回复 36# feynmancgz

Do you have ever deal with customer? Which high volume product you design?

You even don't understand what I am talking about.

Normally, the product will ask maximum cap value. sometimes, the load the cap will be larger than miller cap. since gm*ro=10 under sub-micro process. you can not afford too large Cc.

vdslafe · 发表于 2013-10-25 00:22:47

本帖最后由 vdslafe 于 2013-10-25 00:24 编辑

回复 37# Evanpeng

如果客户要求的范围太大，不就是换一种设计么？再说了又不是所有的运放都是用来驱动板子上的电容。不用把产品设计和教室里面上的混在一起

feynmancgz · 发表于 2013-10-25 01:20:48

回复 37# Evanpeng

Too funny........Teaching is teaching, designing products is designing products.
Why do you always mix them up ?
Seems you know much about designing products.....actually you know nothing, just showing off......

pqzhu88 · 发表于 2013-10-25 04:03:38

别太迷信"直观为王". 推倒熟练了, 自然可以看出零极点位置. 拔苗助长, 得不偿失.

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