Hi Team, in relation to my previous question, this is the schematic of the 2 stage op amp that I'm doing. Do you have any suggestions to better improve this design?

Use a current source instead of resostor for the biasing circuit. In a real circuit, we have biasing currents from other circuits.

Hi Luis, thanks a lot for the feedback. In your first suggestion, how do I calculate what current source I should create to mimic the same resistance?

You don't need to. It was already measured as 22 uA.

What I meant was instead of a resistor, you suggested a current source right? How do you suggest I should do that? I assume its a self-biased transistor?

There is a current source symbol such as the current source symbol

Yes I'm aware of the symbol. I guess the concern is that I will also layout this schem on Magic, and for practical uses I used a resistor so I can lay this out on magic as if it was for fabrication.

Then you should design a constant-gm biasing circuit.

Thanks for sharing this Luis

I don't know what this current mirror biasing you're mentioning. The resistor only connected between the positive supply and current mirror input is a bad idea because any error in the typical supply voltage will change the biasing current and the amplifier bandwidth. Its power supply rejection will be decreased too. At least it's a simple solution and doesn't have start up issues.

Thanks for the inputs Luis. The current mirrors I'm mentioning is the self biased current source that you've shared.

You can replace your resistor with that