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:
Mar. 09, 2010
Filed:
Apr. 18, 2005
Ryo Ando, Hitachinaka, JP;
Ryo Ando, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Unwanted electromagnetic waves are eliminated in a frequency output circuit comprising an open-collector output terminal whereby radio noise can be reduced. A frequency output circuitcomprises an open-collector transistor Qwith an open-collector output terminal connected to a pull-up resistor Rf connected to an external power supply Vex. A current limiting circuitlimits a current through the output terminal such that a high potential and a low potential of the output waveform of a frequency signal outputted by an output circuitare smoothly switched. The current limiting circuitis formed by a differential pair circuit of transistors Qand Qeach with a resistor provided in the emitter thereof, and a current mirror circuit comprising an open-collector transistor, for example.