Tunable Bandwidth Third Order Switched-Capacitor with Multiple Feedbacks Filter for Different Center Frequencies

Abstract

This paper proposes third order tunable bandwidth active Switched-Capacitor filter. The circuit consists of only op-amps and switched capacitors. The circuit is designed for circuit merit factor Q = 10. The proposed circuit implements three filter functions low pass, band pass and high pass simultaneously in single circuit. The filter circuit can be used for both narrow as well as for wide bandwidth. For various values of cut-off frequencies the behaviour of circuit is studied. The circuit works properly only for higher central frequencies, when f 0 > 10 kHz.

An Optimized Design Methodology &Synthesis for Stability of 3rd-Pole Current-Mode Active-R Filter

“…In filter circuit designs, current-mode filters are becoming popular since they have many advantages compared with their voltage-mode counter parts, the current-mode filters have large dynamic range, higher bandwidth, greater linearity, simple circuitry, and low power consumption etc. [4][5][6].Current-mode filter theoretically should exhibit high output impedance (Ideally infinite) and low input impedance (Ideally Zero) [4][5][6][7][8][9][10].In this filter, we use at least ten passive components such as resistor and three active components such as operation amplifier to realize -pole current-mode active-R filter.…”