Active filters with zero transfer function sensitivity with respect to the time constants of operational amplifiers

Author

Budak, Aram ; Wullink, Gerhard ; Geiger, Randall L.

Volume

27

Issue

10

fYear

1980

fDate

10/1/1980 12:00:00 AM

Firstpage

849

Lastpage

854

Abstract

Most second-order RC active filters show a marked dependence on the gain-bandwidth product (GB) of operational amplifiers (OA\´s) when the $\\omega _0$ to be realized is greater than 1 percent of GB and $Q > 10$ . Here designs are given that are virtually independent of OA\´s when $\\omega _0< 0.01$ GB and $Q < 10$ . Even for $\\omega _0=0.05$ GB and $Q=10$ , the center frequency shift due to OA\´s is less than 0.1 percent. This desirable result is achieved by designing filter amplifiers which have zero first-order sensitivities with respect to the time constant $\\tau = 1/GB$ of the OA\´s used in the design. As a result, the filter transfer function has also zero first-order sensitivity with respect to $\\tau$ . General criteria for such designs are given. Experimental results show excellent agreement with theory.

Keywords

Active filters; Active filters, RC; Network sensitivity optimization; Active filters; Bandwidth; Circuits; Frequency; Impedance; Operational amplifiers; Resistors; Transfer functions;

fLanguage

English

Journal_Title

Circuits and Systems, IEEE Transactions on

Publisher

ieee

ISSN

0098-4094

Type

jour

DOI

10.1109/TCS.1980.1084725

Filename

1084725