The Design Of Programmable Switched-Capacitor Filter

The filter technique is an important branch of signal processing for all the time. In today's IC fabricating techniques, the passive filters occupy too much area, and the active RC filters cannot provide sufficient accuracy, so the switched-capacitor filters become the research focus of filters. The theory of the SCF is becoming perfect with the development of the theory of the switched-capacitor networks. Since the high precision and reliability, easy to be realized by integrated circuits, in addition to less volμme, less weight, convenient to realize and program, and non-impedance matching, SCF is used in many applications which involve almost all the applications in signal processing. There is very important academic and practice means in the research and design of SCF.At first, the paper gives a review of the research background and actuality of the filter's design and explains the principles of switched-capacitor networks. Then, the kind of filters and design principles are proposed. At the same time, the methods of filter's realization and the z-domain transfer function are in the issue. One of the difficulties of the filter design in this paper is how to construct the circuit configuration and the programmable capacitor array. The operational amplifier is also a very important part of the SCF, so a low power high accuracy high speed and high dynamic range op-amp is given. At last, the filter's simulation and layout are developed.The most work of this paper is focus on how to design a pass band and center frequency programmable SCF based on the characteristics of power line communication. Because of the particularity of power line communication, the circuit configuration and capacitor array are different of the traditional one. The proposed circuit configuration and capacitor array can also be used to other intermediate frequency and low frequency filters.Finally, the paper draws a conclusion of the work and puts forward the more work of the study of the programmable SC filter.