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:
Jun. 18, 1996
Filed:
Nov. 21, 1994
Applicant:
Inventor:
Michael X Maida, San Jose, CA (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
327534 ; 327535 ; 327563 ;
Abstract
A simple operational amplifier is coupled to a pair of resistors such that a positive reference voltage is reliably converted to a negative voltage. The op amp includes a differential pair of pnp transistors to which is connected a npn transistor connected as an emitter follower. The op amp is constructed and operated such that the bases of the pnp transistors and the collector of the npn transistor never fall below ground voltage.