The circuit includes four transistors, each transistor being connected at its emitter to a different one of four switches arranged in a bridge configuration. The four transistors are paired, each pair including a first transistor connected at its emitter to the collector of the second transistor. The conduction of the first transistor of one pair and of the second transistor of the other pair is controlled by the same signal and the conduction of the second transistor of said one pair and the first transistor of the other pair is controlled by the complement of said signal. The two transistors of each pair produce complementary signals at their emitters and conduct current for all signal conditions.