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:
Jul. 25, 1989
Filed:
Oct. 28, 1987
Dennis P O'Neill, Mountain View, CA (US);
Carl T Nelson, San Jose, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
A current limit circuit is provided which may be used to limit the current conducted by a pass transistor in a low dropout voltage regulator circuit having no ground terminal. The output current of the regulator is sensed by a low value resistor in the collector of the transistor. The voltage developed across the resistor is proportional to the output current of the regulator, and is used to vary a current ratio which sets the current limit value. The gain of the current limit loop is increased by providing positive feedback during current limiting. A foldback network is provided which reduces the current limit value at higher input/output voltage differentials. The feedback provided by the foldback network has a breakpoint which is sensitive to the operating temperature of the regulator circuit.