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:
Nov. 27, 1979
Filed:
Sep. 21, 1977
Robert C Dobkin, Hillsborough, CA (US);
Robert A Pease, San Francisco, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A voltage regulator including a current regulator for maintaining predetermined currents in the voltage regulator is disclosed. The voltage regulator includes an output terminal for providing an output voltage; an adjustment terminal; and a control circuit connected to the output terminal at a level that differs from the voltage at the adjustment terminal by a predetermined voltage difference. The control circuit of the voltage regulator includes a resistive divider coupled between the output terminal and the adjustment terminal; a pair of transistors having their collectors connected in common and their bases respectively coupled to the resistive divider to provide a portion of the voltage difference between the output terminal and the adjustment terminal across their bases. The two transistors are adapted for operating at different current densities for providing a predetermined ratio in current flow through the pair of transistors when the voltage difference between the output terminal and the adjustment terminal is the predetermined voltage difference. The control circuit further includes a high-gain amplifier circuit connected to the emitters of the pair of transistors and to the output terminal for driving the output terminal to a maintained voltage level at which the current flow through the pair of transistors is at the predetermined current ratio and the voltage difference between the output terminal and the adjustment terminal is the predetermined voltage difference. The disclosed voltage regulator is useful as a negative voltage regulator.