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:
Apr. 25, 1995
Filed:
Mar. 25, 1993
Applicant:
Inventor:
James B Cecil, Santa Clara, CA (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F / ;
U.S. Cl.
CPC ...
323315 ; 323312 ; 323314 ;
Abstract
An integrated circuit voltage regulator employs a PNP pass transistor to produce a low dropout voltage. Saturation in the pass transistor produces excessive substrate current which appears in the form of wasted current which lowers the regulator efficiency. A current conducted by the sat catcher circuit is employed to avoid pass transistor saturation. The sat catcher is controlled dynamically so the dropout voltage is minimized and the voltage regulator maintains good performance at high regulator output currents.