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. 24, 1991
Filed:
Jan. 02, 1990
John E Hanna, Mesa, AZ (US);
Motorola, Inc., Tempe, AZ (US);
Abstract
An integrated filter having a controllable frequency response includes a pair of cascaded differential transconductance amplifiers with the differential outputs of the first one of the pair being coupled to the differential inputs of the second one via coupling resistors and the differential inputs of the first one being coupled to inputs of the filter via input coupling resistors. The differential outputs of the second transconductance amplifier are coupled both to outputs of the filter and are fed back to the respective differential inputs of the two amplifiers to provide multiple inputs such that the damping factor of the filter is controllable for adjusting the filter frequency transfer function by varying the ratio of the coupling resistor value to the feedback resistor value while the damping factor is independent of the natural resonant frequency of the filter. Series coupled integrating capacitors are coupled across the differential outputs of both pairs of amplifiers with the interconnection therebetween return to ground.