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:
Dec. 31, 1991
Filed:
Aug. 21, 1989
Derek F Bowers, Sunnyvale, CA (US);
Douglas S Smith, Sunnyvale, CA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A first Schottky diode is connected between the source of a first enhancement JFET and a low voltage line. The drain of the first enhancement JFET is connected through a first active load current source to a high voltage line, and also through a second Schottky diode and a second active load current source to the low voltage line. The first Schottky diode produces a voltage drop which maintains the source of the first enhancement JFET positive with respect to the low voltage line. The second Schottky diode produces a voltage drop complementary to that of the first Schottky diode, which causes the circuit to produce an output voltage across the second current source having a logically low level close to that of the low voltage line. This low output voltage positively turns off a first enhancement JFET of a next stage even at elevated temperatures where the voltage threshold is close to zero, since the source of the first enhancement JFET is held positive at one diode drop above the low voltage line by the first Schottky diode. A second enhancement JFET may be connected to supply current which maintains the first Schottky diode conductive at all times, and also to provide positive feedback to the first enhancement JFET by source coupling through the resistance of the first Schottky diode which enhances switching.