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. 18, 2004
Filed:
Nov. 05, 2002
Renesas Technology Corp., Tokyo, JP;
Abstract
A capacitance measurement method is provided which is capable of measuring an accurate capacitance value even if a leakage current on a level that cannot be ignored occurs in a capacitance to be measured. In step S , a test current IC is measured by using a normal PMOS gate potential as a PMOS gate potential for providing on/off control of PMOS transistors in a predetermined cycle. In step S , a current IC is measured by using, as the PMOS gate potential, a multiplied on-time PMOS gate potential, the “L” period and fall time of which are integral multiples of those of the normal PMOS gate potential. In step S , based on the currents IC , IC , a leakage current IR is eliminated and the amount of capacity current CIC consisting only of a capacitance current component IC is calculated. In step S , a target capacitance is obtained based on the capacity current CIC and a charge frequency f obtained in step S