Professor made one mistake!! Keeping overdrive less actually increases your random offset. ΔI= gm ΔV, if there is any mismatch in the two branch currents of a diff amp it gets reflected as an offset voltage at its input. I ∝ (Vgs-vth)^2 ; If the diff pair has a mismatch of +/- 10mV in it's Vth then ΔI will be more if Vgs is comparable to Vth. So always keep Vov more to reduce standard deviation in offset. You can also see how high gm helps!!
Professor made one mistake!!
Keeping overdrive less actually increases your random offset.
ΔI= gm ΔV, if there is any mismatch in the two branch currents of a diff amp it gets reflected as an offset voltage at its input.
I ∝ (Vgs-vth)^2 ; If the diff pair has a mismatch of +/- 10mV in it's Vth then ΔI will be more if Vgs is comparable to Vth. So always keep Vov more to reduce standard deviation in offset. You can also see how high gm helps!!
Very nice sir
nice sir Ji
gracias