Circuit for connecting a first node to a second or third node as a function of the potential of the latter, for controlling of the potential of an insulation region in an integrated circuit as a function of the substrate voltage

摘要

In a switching circuit suitable for connecting a first circuit node (1) to a second (2) or to a third (3) circuit node in relation to the latter's potential, particularly for controlling the potential of an insulation region of an integrated circuit in relation to the substrate's potential, there is a first NPN bipolar transistor (T1) with the function of a switch having the collector connected to the first circuit node (1) and the emitter connected to the second circuit node (2) and a second NPN bipolar transistor (T2) with the function of a switch having the collector connected to the first circuit node (1) and the emitter connected to the third circuit node (3). There are means (D1, T5, T6) for maintaining the base of the second transistor (T2) at a constant pre-set bias voltage.