[SOLVED] biasing of class of amplifier

[surya92]

why biasing of general amplifier is more complex than voltage follower biasing??

 

[johnjoe]

Which type of amplifier you mean. op-amps?

 

[goldsmith]

why biasing of general amplifier is more complex than voltage follower biasing??

Hi surya92
Can you please tel us more about your question ? i think it is really hard to judge about your question and also trying to answer it . please clarify it .

Best Wishes
Goldsmith

 

[surya92]

thank u gold smith for ur reply....
i saw that the biasing(feed through biasing) of class AB amplifier(CMOS voltage follower) is simpler than CMOS common source amplifier but why it is complex to bias the common source amplifier..?

 

[goldsmith]

thank u gold smith for ur reply....
i saw that the biasing(feed through biasing) of class AB amplifier(CMOS voltage follower) is simpler than CMOS common source amplifier but why it is complex to bias the common source amplifier..?

Hi again
Why common source is complex to being supplied ? it is simple . in a common drain class AB amplifier , you'll need to supply GS of two mosfet . and because they are tied together and at last tied into the load it is easy to supply the required threshold voltage for both of them .
But in a common source , both of the sources have been tied into the supplies ( one of them into the +VDD and the other one to -VDD ) so you will need to bias them independently and of course if both of them be turned on ( which is very possible ) the out put signal will be distorted as well ! just draw both of the arrangements and try to think about what i told and compare them together .
Best Wishes
Goldsmith