MOS Transistor as a Current-Controlled Device

In analog design MOS transistors are treated as "insulated gate" devices, i.e. devices with zero DC input current. In the era of deep submicron technologies this assumption is no longer valid. In transistors with ultra-thin gate oxide gate tunneling current is no longer negligible, and the gate current can be treated as the input signal. In this paper the properties of a MOS transistor as a current-controlled device are investigated. A "quasi-Darlington" configuration of two MOS devices is proposed and its applications to simple amplifier stages is discussed.