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:
May. 20, 1997
Filed:
Jul. 28, 1995
Akio Fujikawa, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A frequency and phase comparator has a first flip-flop and a second flip-flop. Logical calculation between the outputs of these flip-flops is performed by an AND circuit, and the first and second flip-flops are reset by the output of the logical calculation. The first and second flip-flops receive periodic signals at their clock terminals. When the periods of the output pulses of the first and second flip-flops are short, a circuit driven by the pulses sometimes cannot operate correctly. To prevent this, a pulse generating circuit is provided which receives a first periodic signal and a second periodic signal to generate a pulse signal of a predetermined width, and the pulse signal is added to the outputs of the first and second flip-flops.