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:
Apr. 05, 2005
Filed:
Jun. 03, 2003
Kimitoshi Niratsuka, Kawasaki, JP;
Kimitoshi Niratsuka, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
On a semiconductor device, fabricated are a VCOA, an frequency divider by integer R, a frequency divider by integer (P×N+A)wherein each of P, N and A is an integer, A is variable and A<N, a phase comparator, and a charge pump. A low pass filterhaving been confirmed to have standard characteristics is externally added to the semiconductor deviceto construct a PLL circuit to be tested. The frequency divideris of a pulse swallow type and has a control input for setting the integer A at ones in the vicinity of a value in normal use by user. The control input is connected to external terminals Dand Dof the semiconductor devicefor simplifying a test. The semiconductor deviceis judged whether it is acceptable or not in quality by checking whether or not the PLL circuit enters into a locked state within a given period in each cases of A=Aand A=A, where A<A<Aand Ais a value in normal use by user.