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. 22, 1993
Filed:
Dec. 17, 1991
Duane E Galbi, Jericho, VT (US);
Russell J Houghton, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A voltage reference circuit that produces an output offset from a supply voltage by approximately two volts, the output being relatively stable in the face of vacillations in the external power supplies. The first leg of the circuit utilizes devices having differing Vt's to produce an internal reference of one volt below Vdd. In a first embodiment of the invention, the second leg has a first device that is diode connected, wherein the gate receives the internal reference and the source is at the high power supply, and a second high Vt diode connected device. The two devices are matched to have the same overdrive current, which is at a voltage that is a function of the difference between the gate-to-source voltage of the first device and the threshold voltage of the first device. Thus, the output is a function of the overdrive to, and the diode drop across, the second high-Vt device.