1. A logic circuit comprising a plurality of basic circuits each including at least one single-collector driver transistor provided with a clamping Schottky diode, the emitter of said driver transistor being grounded, the base of said driver transistor being used as an input terminal and the collector thereof being used as an output terminal for said basic circuit, each of said basic circuits further including a constant current load transistor coupled to said output terminal of each said basic circuit, wherein the output terminal of a preceding stage basic circuit is coupled directly to the input terminal of the subsequent stage basic circuit, said logic circuit further comprising means for adjusting the amplitude of said constant current provided by each of said constant current load transistors to operate the driver transistor of the subsequent stage, with said clamping Schottky diode forward biased, in a shallow saturation mode when said subsequent stage driver transistor is in an ON state.