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:
Mar. 20, 2001
Filed:
Mar. 08, 1999
Mamoru Shimazaki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A voltage detection circuit is capable of detecting a low voltage without malfunctioning, and this so even if the voltage is lower than a minimum operating voltage. The voltage detection circuit includes two input terminals, a voltage selecting circuit, and a voltage-detecting integrated circuit (IC). In operation, a standard voltage is input into a first input terminal of the voltage detection circuit and the voltage to be detected is input into the second input terminal. The first terminal voltage is then divided by a voltage divider circuit. This divided voltage and the voltage to be detected are input into the voltage selecting circuit, which outputs one of the voltages to the voltage detecting IC. The voltage detecting IC compares the input voltage to a detection voltage and outputs a value accordingly. To ensure that the detection circuit will function properly at all times, the voltage selection circuit inputs the divided voltage into the voltage detecting IC when the voltage to be detected falls below the minimum operating voltage.