Sensitivity considerations in a multiple-feedback universal active filter
Abstract
A multiple-feedback universal active filter is presented and evaluated on the basis of its sensitivity performance. This canonic realization provides, simultaneously, second-order low-pass, bandpass, and high-pass outputs that may be combined to implement generalized biquadratic transfer functions. Additionally, it features the capability of local positive feedback to allow Q-enhancement with the ensuing advantages of sensitivity minimization and reduction in RC-element spread. A new analysis technique is developed for the evaluation of omega-0 and Q sensitivities to operational-amplifier (OA) dc gain and gain-bandwidth product. This technique is extended to modify the figure of merit, introduced for sensitivity minimization purposes by Fleischer, and thus leads to easily obtainable expressions for optimum Q-enhancement factor and the corresponding value of Q in the absence of positive feedback. Making use of this sensitivity analysis technique, the new design is compared to two other high-Q filter configurations widely known for their excellent sensitivity characteristics. It is concluded that the new filter exhibits comparable performance especially in higher tolerance applications using wide-bandwidth OA's.
- Publication:
-
IEEE Transactions on Circuits Systems
- Pub Date:
- December 1977
- Bibcode:
- 1977ITCS...24..695M
- Keywords:
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- Electronic Filters;
- Operational Amplifiers;
- Performance Prediction;
- Positive Feedback;
- Q Factors;
- Transfer Functions;
- Amplification;
- Amplifier Design;
- Bandwidth;
- Design Analysis;
- Feedback Circuits;
- Network Analysis;
- Rc Circuits;
- Sensitivity;
- Electronics and Electrical Engineering