Abstract: A first semi-conductor has a first threshold voltage and provides a particular voltage drop across it in its saturated state of operation. A second semi-conductor has a second threshold voltage and provides the particular voltage drop across it in its saturated state of operation. The second semi-conductor may be a native device. The first and second semi-conductors are connected to provide a common flow of current. A current is induced, as by a third semi-conductor, to flow in the second semi-conductor. The first and second semi-conductors are commonly biased to produce a flow of saturated current through them when a current is induced to flow in the second semi-conductor. Each of the first, second and third semi-conductors may be provided with a gate, drain and source. The sources and drains of the semi-conductors may be in series.