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Question about opamp design

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suria3

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Hi,

When we design a opamp for dc application, what is the centered dc voltage to be. Let say my power supply is 1.8V, should I design the opamp output dc voltage to be 0.9V or since in my cmfb i wanted the opamp to work at 0.6V, then i designed the opamp output voltage at 0.6V. I understand that in the feedback loop, any opamp are able to regulate the dc voltage as long the gain is high enough.So, which is the actual value to be.

Suria.
 

caosl

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Generally for the sake of high swing,the opamp's common mode output level is biased at vdd/2. You can set at another level which you want,no problem! Be care the opamp's regulate range, the transistors should not out of saturation region.
 

Sadegh.j

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High voltage swing in my idea should be a primary concern, your bias point should be such that it gives you as much swing as possible.

Obviously, your bias point should not saturate anything. It is usually chosen to be in the middle.

If you really want 0.6v, then go for it.
 

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