Abstract: The device for shielding the electrons injected towards the substrate by an epitaxial pocket which reaches a negative voltage with respect to said substrate, comprises a debiasing transistor arranged in reverse configuration (with collector and emitter swapped) in the same epitaxial pocket reaching a negative voltage. The transistor is connected with its emitter and its collector between the buried layer of the pocket reaching a negative voltage and the substrate, so as to debias the junction formed by the buried layer and the substrate.

Abstract: The collector area of a lateral PNP transistor may be incrementally increased during an electic testing step on wafer of an integrated circuit by purposely forming an auxiliary p-type diffused collector region having fractional dimensions near the primary collector region of the transistor and by permanently shorcircuiting the two regions by means of a "Zener zapping" technique, by forcing a current through the inversely biased base-collector junction utilizing a suitable contact pad connected to the auxiliary collector region to create localized power dissipation conditions sufficient to melt the metal of the respective metal at the adjacent contacts and to form a permanent connection between the two metals. The technique is very useful for adjusting the value of the output current(s) in precision current generating circuits.

Abstract: This integrated device for shielding injected charges in driving circuits for inductive and/or capacitive loads comprises four integrated structures including a first barrier region with high resistivity which surrounds the buried layer of the epitaxial flyback pocket which may be set at a potential lower than ground on the side of the buried layer which faces the driving circuit pocket; a first charge collecting region provided in the epitaxial flyback pocket; a third low-loss diode structure, formed in an epitaxial pocket which is isolated from the flyback pocket and is arranged between the latter and the driving circuit, and connected so as to clamp the voltage between the epitaxial flyback pocket and the substrate to the diode direct conduction voltage; and, finally, a last barrier structure formed by a charge collecting region connected to the supply voltage.

Abstract: The structure of a vertical PNP transistor with isolated collector is modified by forming a P-type diffusion outside the perimeter of a sinker collector diffusion to form an auxiliary collector capable of detecting the injection of current toward the substrate when the integrated transistor saturates. The current gathered by said auxiliary collector is used for activating a saturation limiting circuit formed by an NPN transistor which is switched-on when said said current gathered by said auxiliary collector reaches a threshold value and which in turn switches-on a PNP transistor having an emitter and a collector connected respectively to the emitter and to the base of the PNP vertical transistor with isolated collector for reducing the driving base current thereto.