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:
Oct. 20, 1981
Filed:
Jun. 29, 1979
Robert J Simcoe, Liverpool, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
MOS circuitry conducting constant current at high voltage comprises first, second and third depletion mode MOSFETs connected in a loop, with their gates joined at the junction of the second and third MOSFETs. A control circuit is coupled to the junction of the first and second MOSFETs. The drain of an enhancement mode fourth MOSFET is connected to the junction of the second and third MOSFETs while its source remains unconnected. With high voltage applied to the junction of the first and third MOSFETs, and with the control circuit essentially nonconductive, the fourth MOSFET experiences diode breakdown, thereby acting as a high voltage source which prevents gate oxide rupture on the first, second and third MOSFETs and causing the first and second MOSFETs to become nonconductive until the control circuit is again rendered conductive.