Hi, the bias currents are generally decided by the regenerative time. The differential current ~ gmrp --> reduce the regenerative time incr bias currents & during small signal differential regenerative voltage -->gm*rp*t/cp
If say the swing is 0.4v , capacitance c is 0.5p , let the regenrative time is 0.05n second , as Q=i*t, Q=c*Vswing, so I=C*vSwing/Treg , I tried doing this but regeneration is not working , corect me if i am wrong