The minimum supply voltage in low-voltage circuits can be defined as Vsup,min = 2(Vgs+Vsat) [1]. Low-voltage circuits are able to operate on a supply voltage of two stacked gate-source voltages and two saturation voltages. Differential amplifiers are biased with a transistor feeding a differential pair, where the current level is set by the bias transistor. The minimum input voltage in a NMOS i...