Gallium-arsenide LSI logic elements with an expanded efficiency range

The authors study the problem of how to precisely generate the threshold voltage of the field-effect transistors. The problem is aggravated by the fact that the load elements of the logic gate are realized using transistors which are normally in the open state. The requirements on the threshold-voltage tolerances may be significantly decreased by using a new type of complex load element consisting of two field-effect transistors: a primary and a secondary. The primary load transistor and the switching transistor are manufactured under identical conditions and have equal threshold voltages. The secondary transistor is normally open and serves to guarantee the operation of the primary load transistor in the gate current mode. The current of the secondary transistor is selected several times lower than the current of the primary load transistor. The use of complex loads in LSI logic elements based on normally open field-effect transistors stabilizes power consumption and economizes the area occupied by the gate on the crystal.