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:
Jan. 26, 1993
Filed:
Oct. 05, 1990
Roberto Gariboldi, Lacchiarella, IT;
Alberto Gola, Broni, IT;
SGS-Thomson Microelectronics S.r.l., Agrate Brianza, IT;
Abstract
An output stage with a protection circuit against negative overvoltage at its output terminal, having a transistor with collector output and with the emitter connected to a reference voltage line; a diode for protection against negative overvoltages present on the output is arranged between the collector and the output of the stage. In order to give the output of the stage a presettable minimum voltage level, the reference voltage line is set to a preset voltage which differs from the ground voltage. For this purpose, the circuit comprises an operational amplifier in a voltage-follower configuration, the output whereof is connected to the reference voltage line, a diode which is connected between the ground and the non-inverting terminal of the operational amplifier, and a current source which is connected between the non-inverting input of the operational amplifier and a negative supply line.