open loop BW(A(s)*beta)=1/time constant (close loop) = 1/(RC), BW = Wu = 2* pi *Ft
open loop BW (A(s)* beta) = 1/(cloce loop time constant)
=> BW =1/T
BW (A(s)*Beta)= open loop Wu = ( gm/C )* Beta = 2 * pi * Ft
Ft = unit gain frequency of A(s)*Beta
gm = input differential pair`s gm, C = compensation capacitor
T = close loop time constant