Do you have any suggestions on how to layout an Gain boosted Amp?
I'm not so sure if I should place the two differential gain enhancing amplifiers in a stacked fashion between the PMOS and the NMOS tail current source of the main amp. Or I could place the gain enhancing amp on oneside of the main amp and the other one on the otherside? Stacking will give a more symmetric form.
I'm not sure what you mean here.
If I stack them, then the layout get vertically long.
But the two boost amps are different (one is PMOS folded, other is NMOS folded) and if I place them at the sides of the main opamp the symmetry is not maintained. What do you mean by repetition?
Repetition is only possible for equal blocks. This means copying - not mirroring! - the block from the left side to the right side (or vice versa).
I think absolute symmetry is not possible and not so important in your case. Take the alignment
- which better suits the required aspect ratio
- or
- if more important because of frequency consideration - which uses shorter connections, i.e. smaller parasitic caps.