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:
May. 21, 2002
Filed:
Mar. 17, 2000
Lawrence Henry Ragan, Richardson, TX (US);
Mark Richard Gehring, Portland, OR (US);
RadioCom Corporation, Portland, OR (US);
Abstract
A high precision current control circuit (current mirror) is disclosed. As in prior current mirrors, a reference voltage is generated from the input reference current. An operational amplifier is placed between the reference diode and the bases of the controlled transistors to provide precise reproduction of the reference voltage with ample current to drive many controlled current sources or current sources with high multiplication ratios from the reference current. As compared to prior emitter follower drivers, a lower voltage threshold of operation from an external proportional control results. Lower power supply voltage is supported, since one diode drop is removed from the reference current path.