hi pp,
The AD8091 is NOT suitable for your project.... look at the datasheet for maximum supply voltage range

E

 

Where this 20mA comes from?

In post #14 you specified a 20mA output current.
The current comes from the supply, via the op-amp

 

In post #14 you specified a 20mA output current.
The current comes from the supply, via the op-amp

Sorry, I have written wrong way.

I have to achieve the 5.2V with the 20mA current at the output stage, this is requirement of the project. I know how to calculate and design the circuit to achieve the 5.2V as a output, But I don't know how to calculate and design the circuit to achieve the output current of 20mA maximum, but now I knew the formula which you provided to calculate the output current. If my output load is 10k, then, according to the formula the output current is 5.72mA. Therefore, do I need to change the value of R2 to achieve the 20mA current?.

 

All you need to do is to make sure that the op-amp has sufficient output current. It can output 45mA. You are using 10mA in the feedback resistor. Therefore there is 35mA remaining, plenty to achieve 20mA output.

but. . .
your op-amp is DEAD because you have exceeded its absolute maximum power supply voltage, so the only output you will get is smoke.

 

hi pp
This is using a suitable OPA, with Rin and Rfb at 1k.
Shows the current values.

Find a OPA that will deliver at least 30mA on its output pin.

E