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:
Nov. 28, 1989
Filed:
Nov. 08, 1988
Hiromu Enomoto, Sendai, JP;
Hirofumi Dohgome, Kokubu, JP;
Masao Kumagai, Sendai, JP;
Toru Nakamura, Kushikino, JP;
Kimitaka Yoshiyama, Kagoshima, JP;
Fujitsu Limited, Kawasaki, JP;
Kyushu Fujitsu Electronics Limited, Kagoshima, JP;
Abstract
A Schmitt trigger circuit has a first transistor for inversion having a base supplied with an input voltage. A level shift diode shifts an emitter voltage of the first transistor from a reference level, and a second transistor for switching has a collector and an emitter respectively coupled to an anode and a cathode of the level shift diode. The emitter of the second transistor is coupled to a first power source voltage. A switching part is coupled between a base of the second transistor and a second power source voltage higher than the first power source voltage, for controlling switching of the second transistor. An output circuit is coupled between the first and second power source voltages and supplied with the input voltage through the first transistor for outputting the output voltage. The switching part is controlled responsive to a voltage from the output circuit so as to close when the logic level of this voltage is the high level, thereby turning the second transistor ON.