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:
Sep. 11, 2007
Filed:
Dec. 30, 2005
Yuichi Matsushita, Miyazaki, JP;
Yuichi Matsushita, Miyazaki, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
The present invention provides a pulse width modulation (PWM) circuit comprising an PWM control circuit for setting an output signal to low when a logical level of a oscillation signal at a first input terminal changes from low to high, for resetting the output level to low in response to an effective input signal at a second terminal, a charge and discharge means for charging a first node (node) when the output stays in low, for discharging the stored charge of nodewhen the output stays in high, a comparator (C) for outputting an output signal to the second terminal according to the first node signal and a first reference signal (Vref), a discharge current controlling means for the stored charge on the first node, wherein the discharge current controlling means comprises a bias circuitfor controlling the discharge current based on constant current.