How to assign the biasing value of an opamp?

[alexang1983]

I need to set the biasing values of an op amp but maybe there is a way without calculate all voltages and currents ....If I want for example a 70 dB gain how can I assign the value of biasing?
thanks

 

[Audioguru]

OP AMP BIASING

An opamp's input must be biased at half of its total power supply voltage for the highest symmetrical output swing.

Biasing an opamp has nothing to do with its voltage gain.
Its voltage gain is the ratio of its negative feedback resistor to the other resistor (the input resistor if the opamp circuit is inverting or the resistor to ground if the opamp circuit is non-inverting).

70dB is a lot of gain. Most opamps rolloff the high frequencies and with that much gain then the rolloff will begin at about 200hz with most opamps.

 

[alexang1983]

Re: OP AMP BIASING

How can i get 2.65 points to download the attachments
Please help me

 

[laiza]

Re: OP AMP BIASING

do you have email add so that i can send it you?

Added after 1 minutes:

your points increases as you post or reply others.

 

[alexang1983]

Re: OP AMP BIASING

Yes sure

alex.ang1983@gmail.com

THANK YOU VERY MUCH!!!!!

 

[alexang1983]

Re: OP AMP BIASING

are u ok? I never saw you on line ...you asked me my e-mail

 

[flyingsky]

OP AMP BIASING

just wait a moment,i cannot download it as you.
but maybe i will download it tomorrow.

 

[LvW]

Re: OP AMP BIASING

Alexang1983

In your own interest I suggest you to repeat your question in more detail.
Otherwise you cannot expect to get an appropriate answer.

For instance, are you designing an opamp by yourself or do you intend to use an existing integrated opamp device ?

 

[jony130]

Re: OP AMP BIASING

Here you have the same file that laiza attach but no points is needed
**broken link removed**