Switched Capacitor Fractional Step Butterworth Filter Design
Switched capacitor fractional step filter design of low pass filter prototypes with Butterworth characteristics is reported in this work for the first time. This is achieved using discrete time integrators which implement both the bilinear and the Al Alaoui s to z transformations. Filters of orders 1.2, 1.5 and 1.8 as well as 3.2, 3.5, and 3.8 are designed and verified using transistor level simulations with Cadence on AMS $0.35\\upmu $0.35mm CMOS process. Digital programmability of the fractional step filters is also achieved.
Circuits Syst. Signal Process.