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.

Date of Patent:
Mar. 23, 1999

Filed:

Sep. 29, 1997
Applicant:
Inventors:

Shoji Yasui, Hamamatsu, JP;

Hideyuki Yamada, Hamamatsu, JP;

Assignee:

Yamaha Corporation, Hamamatsu, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F / ;
U.S. Cl.
CPC ...
327530 ; 327538 ; 327540 ;
Abstract

A reference voltage generating circuit is provided with a reference voltage output terminal, a voltage dividing circuit that divides a voltage supplied from a power source, and an integrating circuit having a given time constant, for integrating a voltage of the divided voltage output terminal of the voltage dividing circuit and generating a reference voltage as a result of integration to the reference voltage output terminal. A high-speed charging circuit is connected to the reference voltage output terminal, for charging the integrating circuit at a high speed when the power source is turned on, to elevate a voltage of the reference voltage output terminal at a speed higher than a speed determined by the time constant of the integrating circuit. A comparator circuit compares the voltage of the divided voltage output terminal with the voltage of the reference voltage output terminal, and turns off the high-speed charging circuit when a difference between the voltage of the divided voltage output terminal and the voltage of the reference voltage output terminal becomes equal to or smaller than a predetermined level.


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