Bipolar monolithic integrated digital pushpull output stage - has dual emitter transistor connected in series with output transistor with constant current source

摘要

The bipolar monolithic integrated digital pushpull output stage has the digital input signal (4) applied to the base of a second transistor (2) in series with a complementary sixth transistor (6) across the supply poles. A first transistor (1) is connected by its base to the common-collector connection of the previous two transistors and its emitter forms the output (5). A dual-emitter transistor (3) is connected by its collector to the emitter output of the first transistor, by its base to a seventh transistor (7), by its first emitter to the common-collector connection and by its second emitter to its own base. The sixth and seventh transistors each act as a constant current source.