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:
Jun. 04, 1996
Filed:
Mar. 06, 1995
Nippon Precision Circuits Inc., Tokyo, JP;
Abstract
To provide a resistor array circuit device and variable gain device which make possible precise setting of attenuation factors and the like as well as prevention of generation of gridge noise, a resistor array circuit device has resistors R1.sub.1 to R1.sub.n-1, each with a resistance value R, resistors R2.sub.1 to R2.sub.n, each with a resistance value aR, resistor R3 having a resistance value (l+b)R, switches SW.sub.1 to SW.sub.n for switching connection of resistors R2.sub.1 to R2.sub.n to a terminal T3 or a terminal T4, and a control circuit for controlling switches SW.sub.1 to SW.sub.n so that resistors R2.sub.1 to R2.sub.m-1 on a terminal T1 side of an arbitrary resistor R2.sub.m are connected to terminal T4 and resistors R2.sub.m to R2.sub.n on a terminal T2 side of resistor R2.sub.m are connected to terminal T3, the values of the a and b being determined based on b={-1+(1+4a).sup.1/2 }/2 and 1/2<a/(1+a+b). A variable gain device uses the above resistor array circuit device with an operational amplifier Op and a resistor R4.