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. 13, 1989
Filed:
Sep. 29, 1988
Peter A Gardner, Harestock, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A current-controlling circuit for producing either a constant current, independent of supply potential or a current which decreases with increasing supply potential and vice-versa. Three devices are connected together at a point such that the current in the first device and the current in the third device form the current in the second device. The current flowing in the first device is a mirror of the current flowing in a fourth device. When the supply potential increases, the increase in current in the first device at least equals the increase in current in the second device, so that the current in the third device does not increase. If the current in the third device decreases with increasing supply potential, it may be mirrored into subsequent devices which may then pass a constant current. The circuit may include an amplifying current mirror so that any change in current flowing in the first device is an amplified version of the change in current in the fourth device. The circuit may be implemented in field effect transistor technology. The amplitude of the current produced by the circuit is dependent on an input control voltage which is controlled by external means.