A High Order Switched-Capacitor Bandpass Filter with Passband Tunable and -76dB/Octave Attenuation at Transition Band

A high order switched-capacitor bandpass filter (SCBF) with passband tunable is presented in this paper. The proposed differential SCBF consists six biquad sub-filters, non-overlapping clock and voltage reference. The clock controls switches in the SCBF. The cascaded six biquad sub-filters are order to improve the rejection at the filter transition band. By changing the input clock frequency, the passband of the SCBF can be adjusted from 2KHz to 2MHz. The SCBF achieves no more than 0.3dB ripple in the passband, and at least -76dB/octave attenuation at transition band.