The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 09, 1993
Filed:
Mar. 26, 1991
Franco Bertotti, Milan, IT;
Paolo Ferrari, Gallarate, IT;
Abstract
A circuital arrangement which comprises a vertical PNP transistor with insulated collector, which has a P-type collector structure surrounded by an N-type well and forms a junction therewith. In order to prevent latch-ups of the parasite SCR which is formed by the structure of the vertical transistor with insulated collector without limiting the voltage which can be applied between the collector and the emitter thereof to values below the intrinsic breakdown ones, the circuital arrangement comprises an auxiliary PNP transistor the emitter whereof is short-circuited with the emitter of the vertical PNP transistor, the base whereof is connected to the base of the vertical PNP transistor and the collector whereof is connected to the N-type well, and operates as a switch which biases the N-type well at a voltage which is close to the voltage of the emitter of the vertical PNP transistor when the latter is saturated, reverse-biasing the collector/N-well junction, and opens when the vertical PNP transistor is off, limiting the voltage applied to the collector/N-well junction.