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How to enhance the DC gain of an CMOS opamp?

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leonken

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Are there some methods to enhance the gain of an CMOS opamp?
I designing an CMOS opamp. The architecture is a simple OTA with an Nmos diff. pair.
 

OpAmp

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The first method is to use cascode transistors instead of simple common source amplifier.

Then, you can use Gain-boosting method which is described in almost all CMOS analog circuit design books.

OpAmp
 

jwfan

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Ordinarily, decrease the bias current will increase the gain slightly. Or change the W/L to increase the Ro, if your don't want to change the whole topology which have been provided by OpAmp.
 

jluhzw

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YOu can get the methods by refering the documents and the books.
Pray's book "analog integrated circuits analysis and design"
Allen's book "cmos analog circuits design".
 

Chethan

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If you dont want to change the architecture then there are two ways of increasing gain
1)Decrease the biasing current
2)Increase the W of the input n channel diff amplifier
 

sunking

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muti-stage opa too
 

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