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:
Oct. 25, 2011
Filed:
Dec. 21, 2009
Tomohiro Kume, Osaka, JP;
Tomohiro Kume, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A reference voltage generator includes: a reference voltage sourcethat generates a direct-current voltage that is used as a reference; a low-pass filterthat is connected to an output node of the reference voltage source; a first voltage buffer circuitwith an input terminal to which the output node of the reference voltage source is connected and an output terminal to which an output node of the low-pass filter is connected, which has a voltage gain of one time; and a hysteresis comparatorwith one input terminal to which the output node of the reference voltage source is connected and an other input terminal to which the output node of the low-pass filter is connected. At start-up, during a time period in which a voltage difference between an output of the reference voltage source and an output of the low-pass filter exceeds a predetermined value, an output impedance of the first voltage buffer circuit is controlled based on an output signal of the hysteresis comparator. At start-up, the low-pass filter that reduces noise is charged with a low impedance rapidly, and thus an output voltage can be stabilized rapidly.