Switched-Capacitor Fractional-Step Butterworth Filter Design
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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 \(0.35\,\upmu \)m CMOS process. Digital programmability of the fractional-step filters is also achieved.
KeywordsFilter Design Circuit Complexity Filter Prototype Feedback Capacitor Realize Transfer Function
This work was supported by Grant E.029 from the Research Committee of the University of Patras (Programme K. Karatheodori).
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