Protection circuit for bipolar integrated circuit - uses integrated or external diodes to couple IC outputs to constant positive potential corresponding to half base-emitter operating voltage

摘要

The protection circuit uses diodes (8,9,10) for coupling the respective outputs (2,3,4) of the bipolar IC (1) to a conductor (11), exhibiting a potential which is offset by about half the base/emitter voltage (UBE) in the direction of the operating voltage of the IC (1), relative to a reference potential. The potential for the latter conductor (11) can be provided by a constant voltage source (13) used to provide the operating voltage for the bipolar IC (1). The conductor (11) pref. connected to earth via a capacitor (15) with a capacitance of more than 100 mF. USE - For protection against negative voltages at IC outputs and against electromagnetic interference.