An FET including a gate conductor overlying a channel has first and second threshold voltages, respectively of a first and a second magnitude. When the second magnitude exceeds the first magnitude, both threshold voltages become effective concurrently. The FET operates responsive to a gate-source voltage between the gate conductor and source in states that include a non-conductive state. When the magnitude of the gate-source voltage is lower than the first and second magnitudes, the source-drain current is negligible. The first conductive state when the magnitude of the gate-source voltage exceeds the first magnitude and is lower than the second magnitude, the source-drain current operates at ten or more times exceeding the negligible value. When the second conductive state exceeds the magnitude of the gate-source voltage and exceeds the first and second magnitude, the state the source-drain current has a second operating value ten or more times higher than the first.